Move webrtc/{base => rtc_base}

webrtc/base/trace_event.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file under third_party_mods/chromium or at:
 // http://src.chromium.org/svn/trunk/src/LICENSE
 
 #ifndef WEBRTC_BASE_TRACE_EVENT_H_
 #define WEBRTC_BASE_TRACE_EVENT_H_
 
-#include <string>
 
-#include "webrtc/base/event_tracer.h"
-
-#if defined(TRACE_EVENT0)
-#error "Another copy of trace_event.h has already been included."
-#endif
-
-// Extracted from Chromium's src/base/debug/trace_event.h.
-
-// This header is designed to give you trace_event macros without specifying
-// how the events actually get collected and stored. If you need to expose trace
-// event to some other universe, you can copy-and-paste this file,
-// implement the TRACE_EVENT_API macros, and do any other necessary fixup for
-// the target platform. The end result is that multiple libraries can funnel
-// events through to a shared trace event collector.
-
-// Trace events are for tracking application performance and resource usage.
-// Macros are provided to track:
-//    Begin and end of function calls
-//    Counters
-//
-// Events are issued against categories. Whereas LOG's
-// categories are statically defined, TRACE categories are created
-// implicitly with a string. For example:
-//   TRACE_EVENT_INSTANT0("MY_SUBSYSTEM", "SomeImportantEvent")
-//
-// Events can be INSTANT, or can be pairs of BEGIN and END in the same scope:
-//   TRACE_EVENT_BEGIN0("MY_SUBSYSTEM", "SomethingCostly")
-//   doSomethingCostly()
-//   TRACE_EVENT_END0("MY_SUBSYSTEM", "SomethingCostly")
-// Note: our tools can't always determine the correct BEGIN/END pairs unless
-// these are used in the same scope. Use ASYNC_BEGIN/ASYNC_END macros if you
-// need them to be in separate scopes.
-//
-// A common use case is to trace entire function scopes. This
-// issues a trace BEGIN and END automatically:
-//   void doSomethingCostly() {
-//     TRACE_EVENT0("MY_SUBSYSTEM", "doSomethingCostly");
-//     ...
-//   }
-//
-// Additional parameters can be associated with an event:
-//   void doSomethingCostly2(int howMuch) {
-//     TRACE_EVENT1("MY_SUBSYSTEM", "doSomethingCostly",
-//         "howMuch", howMuch);
-//     ...
-//   }
-//
-// The trace system will automatically add to this information the
-// current process id, thread id, and a timestamp in microseconds.
-//
-// To trace an asynchronous procedure such as an IPC send/receive, use
-// ASYNC_BEGIN and ASYNC_END:
-//   [single threaded sender code]
-//     static int send_count = 0;
-//     ++send_count;
-//     TRACE_EVENT_ASYNC_BEGIN0("ipc", "message", send_count);
-//     Send(new MyMessage(send_count));
-//   [receive code]
-//     void OnMyMessage(send_count) {
-//       TRACE_EVENT_ASYNC_END0("ipc", "message", send_count);
-//     }
-// The third parameter is a unique ID to match ASYNC_BEGIN/ASYNC_END pairs.
-// ASYNC_BEGIN and ASYNC_END can occur on any thread of any traced process.
-// Pointers can be used for the ID parameter, and they will be mangled
-// internally so that the same pointer on two different processes will not
-// match. For example:
-//   class MyTracedClass {
-//    public:
-//     MyTracedClass() {
-//       TRACE_EVENT_ASYNC_BEGIN0("category", "MyTracedClass", this);
-//     }
-//     ~MyTracedClass() {
-//       TRACE_EVENT_ASYNC_END0("category", "MyTracedClass", this);
-//     }
-//   }
-//
-// Trace event also supports counters, which is a way to track a quantity
-// as it varies over time. Counters are created with the following macro:
-//   TRACE_COUNTER1("MY_SUBSYSTEM", "myCounter", g_myCounterValue);
-//
-// Counters are process-specific. The macro itself can be issued from any
-// thread, however.
-//
-// Sometimes, you want to track two counters at once. You can do this with two
-// counter macros:
-//   TRACE_COUNTER1("MY_SUBSYSTEM", "myCounter0", g_myCounterValue[0]);
-//   TRACE_COUNTER1("MY_SUBSYSTEM", "myCounter1", g_myCounterValue[1]);
-// Or you can do it with a combined macro:
-//   TRACE_COUNTER2("MY_SUBSYSTEM", "myCounter",
-//       "bytesPinned", g_myCounterValue[0],
-//       "bytesAllocated", g_myCounterValue[1]);
-// This indicates to the tracing UI that these counters should be displayed
-// in a single graph, as a summed area chart.
-//
-// Since counters are in a global namespace, you may want to disembiguate with a
-// unique ID, by using the TRACE_COUNTER_ID* variations.
-//
-// By default, trace collection is compiled in, but turned off at runtime.
-// Collecting trace data is the responsibility of the embedding
-// application. In Chrome's case, navigating to about:tracing will turn on
-// tracing and display data collected across all active processes.
-//
-//
-// Memory scoping note:
-// Tracing copies the pointers, not the string content, of the strings passed
-// in for category, name, and arg_names.  Thus, the following code will
-// cause problems:
-//     char* str = strdup("impprtantName");
-//     TRACE_EVENT_INSTANT0("SUBSYSTEM", str);  // BAD!
-//     free(str);                   // Trace system now has dangling pointer
-//
-// To avoid this issue with the |name| and |arg_name| parameters, use the
-// TRACE_EVENT_COPY_XXX overloads of the macros at additional runtime overhead.
-// Notes: The category must always be in a long-lived char* (i.e. static const).
-//        The |arg_values|, when used, are always deep copied with the _COPY
-//        macros.
-//
-// When are string argument values copied:
-// const char* arg_values are only referenced by default:
-//     TRACE_EVENT1("category", "name",
-//                  "arg1", "literal string is only referenced");
-// Use TRACE_STR_COPY to force copying of a const char*:
-//     TRACE_EVENT1("category", "name",
-//                  "arg1", TRACE_STR_COPY("string will be copied"));
-// std::string arg_values are always copied:
-//     TRACE_EVENT1("category", "name",
-//                  "arg1", std::string("string will be copied"));
-//
-//
-// Thread Safety:
-// Thread safety is provided by methods defined in event_tracer.h. See the file
-// for details.
-
-
-// By default, const char* argument values are assumed to have long-lived scope
-// and will not be copied. Use this macro to force a const char* to be copied.
-#define TRACE_STR_COPY(str) \
-    webrtc::trace_event_internal::TraceStringWithCopy(str)
-
-// This will mark the trace event as disabled by default. The user will need
-// to explicitly enable the event.
-#define TRACE_DISABLED_BY_DEFAULT(name) "disabled-by-default-" name
-
-// By default, uint64 ID argument values are not mangled with the Process ID in
-// TRACE_EVENT_ASYNC macros. Use this macro to force Process ID mangling.
-#define TRACE_ID_MANGLE(id) \
-    webrtc::trace_event_internal::TraceID::ForceMangle(id)
-
-// Records a pair of begin and end events called "name" for the current
-// scope, with 0, 1 or 2 associated arguments. If the category is not
-// enabled, then this does nothing.
-// - category and name strings must have application lifetime (statics or
-//   literals). They may not include " chars.
-#define TRACE_EVENT0(category, name) \
-    INTERNAL_TRACE_EVENT_ADD_SCOPED(category, name)
-#define TRACE_EVENT1(category, name, arg1_name, arg1_val) \
-    INTERNAL_TRACE_EVENT_ADD_SCOPED(category, name, arg1_name, arg1_val)
-#define TRACE_EVENT2(category, name, arg1_name, arg1_val, arg2_name, arg2_val) \
-    INTERNAL_TRACE_EVENT_ADD_SCOPED(category, name, arg1_name, arg1_val, \
-        arg2_name, arg2_val)
-
-// Same as TRACE_EVENT except that they are not included in official builds.
-#ifdef OFFICIAL_BUILD
-#define UNSHIPPED_TRACE_EVENT0(category, name) (void)0
-#define UNSHIPPED_TRACE_EVENT1(category, name, arg1_name, arg1_val) (void)0
-#define UNSHIPPED_TRACE_EVENT2(category, name, arg1_name, arg1_val, \
-                               arg2_name, arg2_val) (void)0
-#define UNSHIPPED_TRACE_EVENT_INSTANT0(category, name) (void)0
-#define UNSHIPPED_TRACE_EVENT_INSTANT1(category, name, arg1_name, arg1_val) \
-    (void)0
-#define UNSHIPPED_TRACE_EVENT_INSTANT2(category, name, arg1_name, arg1_val, \
-                                       arg2_name, arg2_val) (void)0
-#else
-#define UNSHIPPED_TRACE_EVENT0(category, name) \
-    TRACE_EVENT0(category, name)
-#define UNSHIPPED_TRACE_EVENT1(category, name, arg1_name, arg1_val) \
-    TRACE_EVENT1(category, name, arg1_name, arg1_val)
-#define UNSHIPPED_TRACE_EVENT2(category, name, arg1_name, arg1_val, \
-                               arg2_name, arg2_val) \
-    TRACE_EVENT2(category, name, arg1_name, arg1_val, arg2_name, arg2_val)
-#define UNSHIPPED_TRACE_EVENT_INSTANT0(category, name) \
-    TRACE_EVENT_INSTANT0(category, name)
-#define UNSHIPPED_TRACE_EVENT_INSTANT1(category, name, arg1_name, arg1_val) \
-    TRACE_EVENT_INSTANT1(category, name, arg1_name, arg1_val)
-#define UNSHIPPED_TRACE_EVENT_INSTANT2(category, name, arg1_name, arg1_val, \
-                                       arg2_name, arg2_val) \
-    TRACE_EVENT_INSTANT2(category, name, arg1_name, arg1_val, \
-                         arg2_name, arg2_val)
-#endif
-
-// Records a single event called "name" immediately, with 0, 1 or 2
-// associated arguments. If the category is not enabled, then this
-// does nothing.
-// - category and name strings must have application lifetime (statics or
-//   literals). They may not include " chars.
-#define TRACE_EVENT_INSTANT0(category, name) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_INSTANT, \
-        category, name, TRACE_EVENT_FLAG_NONE)
-#define TRACE_EVENT_INSTANT1(category, name, arg1_name, arg1_val) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_INSTANT, \
-        category, name, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val)
-#define TRACE_EVENT_INSTANT2(category, name, arg1_name, arg1_val, \
-        arg2_name, arg2_val) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_INSTANT, \
-        category, name, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val, \
-        arg2_name, arg2_val)
-#define TRACE_EVENT_COPY_INSTANT0(category, name) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_INSTANT, \
-        category, name, TRACE_EVENT_FLAG_COPY)
-#define TRACE_EVENT_COPY_INSTANT1(category, name, arg1_name, arg1_val) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_INSTANT, \
-        category, name, TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val)
-#define TRACE_EVENT_COPY_INSTANT2(category, name, arg1_name, arg1_val, \
-        arg2_name, arg2_val) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_INSTANT, \
-        category, name, TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val, \
-        arg2_name, arg2_val)
-
-// Records a single BEGIN event called "name" immediately, with 0, 1 or 2
-// associated arguments. If the category is not enabled, then this
-// does nothing.
-// - category and name strings must have application lifetime (statics or
-//   literals). They may not include " chars.
-#define TRACE_EVENT_BEGIN0(category, name) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_BEGIN, \
-        category, name, TRACE_EVENT_FLAG_NONE)
-#define TRACE_EVENT_BEGIN1(category, name, arg1_name, arg1_val) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_BEGIN, \
-        category, name, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val)
-#define TRACE_EVENT_BEGIN2(category, name, arg1_name, arg1_val, \
-        arg2_name, arg2_val) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_BEGIN, \
-        category, name, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val, \
-        arg2_name, arg2_val)
-#define TRACE_EVENT_COPY_BEGIN0(category, name) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_BEGIN, \
-        category, name, TRACE_EVENT_FLAG_COPY)
-#define TRACE_EVENT_COPY_BEGIN1(category, name, arg1_name, arg1_val) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_BEGIN, \
-        category, name, TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val)
-#define TRACE_EVENT_COPY_BEGIN2(category, name, arg1_name, arg1_val, \
-        arg2_name, arg2_val) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_BEGIN, \
-        category, name, TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val, \
-        arg2_name, arg2_val)
-
-// Records a single END event for "name" immediately. If the category
-// is not enabled, then this does nothing.
-// - category and name strings must have application lifetime (statics or
-//   literals). They may not include " chars.
-#define TRACE_EVENT_END0(category, name) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_END, \
-        category, name, TRACE_EVENT_FLAG_NONE)
-#define TRACE_EVENT_END1(category, name, arg1_name, arg1_val) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_END, \
-        category, name, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val)
-#define TRACE_EVENT_END2(category, name, arg1_name, arg1_val, \
-        arg2_name, arg2_val) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_END, \
-        category, name, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val, \
-        arg2_name, arg2_val)
-#define TRACE_EVENT_COPY_END0(category, name) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_END, \
-        category, name, TRACE_EVENT_FLAG_COPY)
-#define TRACE_EVENT_COPY_END1(category, name, arg1_name, arg1_val) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_END, \
-        category, name, TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val)
-#define TRACE_EVENT_COPY_END2(category, name, arg1_name, arg1_val, \
-        arg2_name, arg2_val) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_END, \
-        category, name, TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val, \
-        arg2_name, arg2_val)
-
-// Records the value of a counter called "name" immediately. Value
-// must be representable as a 32 bit integer.
-// - category and name strings must have application lifetime (statics or
-//   literals). They may not include " chars.
-#define TRACE_COUNTER1(category, name, value) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_COUNTER, \
-        category, name, TRACE_EVENT_FLAG_NONE, \
-        "value", static_cast<int>(value))
-#define TRACE_COPY_COUNTER1(category, name, value) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_COUNTER, \
-        category, name, TRACE_EVENT_FLAG_COPY, \
-        "value", static_cast<int>(value))
-
-// Records the values of a multi-parted counter called "name" immediately.
-// The UI will treat value1 and value2 as parts of a whole, displaying their
-// values as a stacked-bar chart.
-// - category and name strings must have application lifetime (statics or
-//   literals). They may not include " chars.
-#define TRACE_COUNTER2(category, name, value1_name, value1_val, \
-        value2_name, value2_val) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_COUNTER, \
-        category, name, TRACE_EVENT_FLAG_NONE, \
-        value1_name, static_cast<int>(value1_val), \
-        value2_name, static_cast<int>(value2_val))
-#define TRACE_COPY_COUNTER2(category, name, value1_name, value1_val, \
-        value2_name, value2_val) \
-    INTERNAL_TRACE_EVENT_ADD(TRACE_EVENT_PHASE_COUNTER, \
-        category, name, TRACE_EVENT_FLAG_COPY, \
-        value1_name, static_cast<int>(value1_val), \
-        value2_name, static_cast<int>(value2_val))
-
-// Records the value of a counter called "name" immediately. Value
-// must be representable as a 32 bit integer.
-// - category and name strings must have application lifetime (statics or
-//   literals). They may not include " chars.
-// - |id| is used to disambiguate counters with the same name. It must either
-//   be a pointer or an integer value up to 64 bits. If it's a pointer, the bits
-//   will be xored with a hash of the process ID so that the same pointer on
-//   two different processes will not collide.
-#define TRACE_COUNTER_ID1(category, name, id, value) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_COUNTER, \
-        category, name, id, TRACE_EVENT_FLAG_NONE, \
-        "value", static_cast<int>(value))
-#define TRACE_COPY_COUNTER_ID1(category, name, id, value) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_COUNTER, \
-        category, name, id, TRACE_EVENT_FLAG_COPY, \
-        "value", static_cast<int>(value))
-
-// Records the values of a multi-parted counter called "name" immediately.
-// The UI will treat value1 and value2 as parts of a whole, displaying their
-// values as a stacked-bar chart.
-// - category and name strings must have application lifetime (statics or
-//   literals). They may not include " chars.
-// - |id| is used to disambiguate counters with the same name. It must either
-//   be a pointer or an integer value up to 64 bits. If it's a pointer, the bits
-//   will be xored with a hash of the process ID so that the same pointer on
-//   two different processes will not collide.
-#define TRACE_COUNTER_ID2(category, name, id, value1_name, value1_val, \
-        value2_name, value2_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_COUNTER, \
-        category, name, id, TRACE_EVENT_FLAG_NONE, \
-        value1_name, static_cast<int>(value1_val), \
-        value2_name, static_cast<int>(value2_val))
-#define TRACE_COPY_COUNTER_ID2(category, name, id, value1_name, value1_val, \
-        value2_name, value2_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_COUNTER, \
-        category, name, id, TRACE_EVENT_FLAG_COPY, \
-        value1_name, static_cast<int>(value1_val), \
-        value2_name, static_cast<int>(value2_val))
-
-
-// Records a single ASYNC_BEGIN event called "name" immediately, with 0, 1 or 2
-// associated arguments. If the category is not enabled, then this
-// does nothing.
-// - category and name strings must have application lifetime (statics or
-//   literals). They may not include " chars.
-// - |id| is used to match the ASYNC_BEGIN event with the ASYNC_END event. ASYNC
-//   events are considered to match if their category, name and id values all
-//   match. |id| must either be a pointer or an integer value up to 64 bits. If
-//   it's a pointer, the bits will be xored with a hash of the process ID so
-//   that the same pointer on two different processes will not collide.
-// An asynchronous operation can consist of multiple phases. The first phase is
-// defined by the ASYNC_BEGIN calls. Additional phases can be defined using the
-// ASYNC_STEP macros. When the operation completes, call ASYNC_END.
-// An ASYNC trace typically occur on a single thread (if not, they will only be
-// drawn on the thread defined in the ASYNC_BEGIN event), but all events in that
-// operation must use the same |name| and |id|. Each event can have its own
-// args.
-#define TRACE_EVENT_ASYNC_BEGIN0(category, name, id) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_BEGIN, \
-        category, name, id, TRACE_EVENT_FLAG_NONE)
-#define TRACE_EVENT_ASYNC_BEGIN1(category, name, id, arg1_name, arg1_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_BEGIN, \
-        category, name, id, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val)
-#define TRACE_EVENT_ASYNC_BEGIN2(category, name, id, arg1_name, arg1_val, \
-        arg2_name, arg2_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_BEGIN, \
-        category, name, id, TRACE_EVENT_FLAG_NONE, \
-        arg1_name, arg1_val, arg2_name, arg2_val)
-#define TRACE_EVENT_COPY_ASYNC_BEGIN0(category, name, id) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_BEGIN, \
-        category, name, id, TRACE_EVENT_FLAG_COPY)
-#define TRACE_EVENT_COPY_ASYNC_BEGIN1(category, name, id, arg1_name, arg1_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_BEGIN, \
-        category, name, id, TRACE_EVENT_FLAG_COPY, \
-        arg1_name, arg1_val)
-#define TRACE_EVENT_COPY_ASYNC_BEGIN2(category, name, id, arg1_name, arg1_val, \
-        arg2_name, arg2_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_BEGIN, \
-        category, name, id, TRACE_EVENT_FLAG_COPY, \
-        arg1_name, arg1_val, arg2_name, arg2_val)
-
-// Records a single ASYNC_STEP event for |step| immediately. If the category
-// is not enabled, then this does nothing. The |name| and |id| must match the
-// ASYNC_BEGIN event above. The |step| param identifies this step within the
-// async event. This should be called at the beginning of the next phase of an
-// asynchronous operation.
-#define TRACE_EVENT_ASYNC_STEP0(category, name, id, step) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_STEP, \
-        category, name, id, TRACE_EVENT_FLAG_NONE, "step", step)
-#define TRACE_EVENT_ASYNC_STEP1(category, name, id, step, \
-                                      arg1_name, arg1_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_STEP, \
-        category, name, id, TRACE_EVENT_FLAG_NONE, "step", step, \
-        arg1_name, arg1_val)
-#define TRACE_EVENT_COPY_ASYNC_STEP0(category, name, id, step) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_STEP, \
-        category, name, id, TRACE_EVENT_FLAG_COPY, "step", step)
-#define TRACE_EVENT_COPY_ASYNC_STEP1(category, name, id, step, \
-        arg1_name, arg1_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_STEP, \
-        category, name, id, TRACE_EVENT_FLAG_COPY, "step", step, \
-        arg1_name, arg1_val)
-
-// Records a single ASYNC_END event for "name" immediately. If the category
-// is not enabled, then this does nothing.
-#define TRACE_EVENT_ASYNC_END0(category, name, id) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_END, \
-        category, name, id, TRACE_EVENT_FLAG_NONE)
-#define TRACE_EVENT_ASYNC_END1(category, name, id, arg1_name, arg1_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_END, \
-        category, name, id, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val)
-#define TRACE_EVENT_ASYNC_END2(category, name, id, arg1_name, arg1_val, \
-        arg2_name, arg2_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_END, \
-        category, name, id, TRACE_EVENT_FLAG_NONE, \
-        arg1_name, arg1_val, arg2_name, arg2_val)
-#define TRACE_EVENT_COPY_ASYNC_END0(category, name, id) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_END, \
-        category, name, id, TRACE_EVENT_FLAG_COPY)
-#define TRACE_EVENT_COPY_ASYNC_END1(category, name, id, arg1_name, arg1_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_END, \
-        category, name, id, TRACE_EVENT_FLAG_COPY, \
-        arg1_name, arg1_val)
-#define TRACE_EVENT_COPY_ASYNC_END2(category, name, id, arg1_name, arg1_val, \
-        arg2_name, arg2_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_END, \
-        category, name, id, TRACE_EVENT_FLAG_COPY, \
-        arg1_name, arg1_val, arg2_name, arg2_val)
-
-
-// Records a single FLOW_BEGIN event called "name" immediately, with 0, 1 or 2
-// associated arguments. If the category is not enabled, then this
-// does nothing.
-// - category and name strings must have application lifetime (statics or
-//   literals). They may not include " chars.
-// - |id| is used to match the FLOW_BEGIN event with the FLOW_END event. FLOW
-//   events are considered to match if their category, name and id values all
-//   match. |id| must either be a pointer or an integer value up to 64 bits. If
-//   it's a pointer, the bits will be xored with a hash of the process ID so
-//   that the same pointer on two different processes will not collide.
-// FLOW events are different from ASYNC events in how they are drawn by the
-// tracing UI. A FLOW defines asynchronous data flow, such as posting a task
-// (FLOW_BEGIN) and later executing that task (FLOW_END). Expect FLOWs to be
-// drawn as lines or arrows from FLOW_BEGIN scopes to FLOW_END scopes. Similar
-// to ASYNC, a FLOW can consist of multiple phases. The first phase is defined
-// by the FLOW_BEGIN calls. Additional phases can be defined using the FLOW_STEP
-// macros. When the operation completes, call FLOW_END. An async operation can
-// span threads and processes, but all events in that operation must use the
-// same |name| and |id|. Each event can have its own args.
-#define TRACE_EVENT_FLOW_BEGIN0(category, name, id) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_BEGIN, \
-        category, name, id, TRACE_EVENT_FLAG_NONE)
-#define TRACE_EVENT_FLOW_BEGIN1(category, name, id, arg1_name, arg1_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_BEGIN, \
-        category, name, id, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val)
-#define TRACE_EVENT_FLOW_BEGIN2(category, name, id, arg1_name, arg1_val, \
-        arg2_name, arg2_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_BEGIN, \
-        category, name, id, TRACE_EVENT_FLAG_NONE, \
-        arg1_name, arg1_val, arg2_name, arg2_val)
-#define TRACE_EVENT_COPY_FLOW_BEGIN0(category, name, id) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_BEGIN, \
-        category, name, id, TRACE_EVENT_FLAG_COPY)
-#define TRACE_EVENT_COPY_FLOW_BEGIN1(category, name, id, arg1_name, arg1_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_BEGIN, \
-        category, name, id, TRACE_EVENT_FLAG_COPY, \
-        arg1_name, arg1_val)
-#define TRACE_EVENT_COPY_FLOW_BEGIN2(category, name, id, arg1_name, arg1_val, \
-        arg2_name, arg2_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_BEGIN, \
-        category, name, id, TRACE_EVENT_FLAG_COPY, \
-        arg1_name, arg1_val, arg2_name, arg2_val)
-
-// Records a single FLOW_STEP event for |step| immediately. If the category
-// is not enabled, then this does nothing. The |name| and |id| must match the
-// FLOW_BEGIN event above. The |step| param identifies this step within the
-// async event. This should be called at the beginning of the next phase of an
-// asynchronous operation.
-#define TRACE_EVENT_FLOW_STEP0(category, name, id, step) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_STEP, \
-        category, name, id, TRACE_EVENT_FLAG_NONE, "step", step)
-#define TRACE_EVENT_FLOW_STEP1(category, name, id, step, \
-        arg1_name, arg1_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_STEP, \
-        category, name, id, TRACE_EVENT_FLAG_NONE, "step", step, \
-        arg1_name, arg1_val)
-#define TRACE_EVENT_COPY_FLOW_STEP0(category, name, id, step) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_STEP, \
-        category, name, id, TRACE_EVENT_FLAG_COPY, "step", step)
-#define TRACE_EVENT_COPY_FLOW_STEP1(category, name, id, step, \
-        arg1_name, arg1_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_STEP, \
-        category, name, id, TRACE_EVENT_FLAG_COPY, "step", step, \
-        arg1_name, arg1_val)
-
-// Records a single FLOW_END event for "name" immediately. If the category
-// is not enabled, then this does nothing.
-#define TRACE_EVENT_FLOW_END0(category, name, id) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_END, \
-        category, name, id, TRACE_EVENT_FLAG_NONE)
-#define TRACE_EVENT_FLOW_END1(category, name, id, arg1_name, arg1_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_END, \
-        category, name, id, TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val)
-#define TRACE_EVENT_FLOW_END2(category, name, id, arg1_name, arg1_val, \
-        arg2_name, arg2_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_END, \
-        category, name, id, TRACE_EVENT_FLAG_NONE, \
-        arg1_name, arg1_val, arg2_name, arg2_val)
-#define TRACE_EVENT_COPY_FLOW_END0(category, name, id) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_END, \
-        category, name, id, TRACE_EVENT_FLAG_COPY)
-#define TRACE_EVENT_COPY_FLOW_END1(category, name, id, arg1_name, arg1_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_END, \
-        category, name, id, TRACE_EVENT_FLAG_COPY, \
-        arg1_name, arg1_val)
-#define TRACE_EVENT_COPY_FLOW_END2(category, name, id, arg1_name, arg1_val, \
-        arg2_name, arg2_val) \
-    INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_FLOW_END, \
-        category, name, id, TRACE_EVENT_FLAG_COPY, \
-        arg1_name, arg1_val, arg2_name, arg2_val)
-
-
-////////////////////////////////////////////////////////////////////////////////
-// Implementation specific tracing API definitions.
-
-// Get a pointer to the enabled state of the given trace category. Only
-// long-lived literal strings should be given as the category name. The returned
-// pointer can be held permanently in a local static for example. If the
-// unsigned char is non-zero, tracing is enabled. If tracing is enabled,
-// TRACE_EVENT_API_ADD_TRACE_EVENT can be called. It's OK if tracing is disabled
-// between the load of the tracing state and the call to
-// TRACE_EVENT_API_ADD_TRACE_EVENT, because this flag only provides an early out
-// for best performance when tracing is disabled.
-// const unsigned char*
-//     TRACE_EVENT_API_GET_CATEGORY_ENABLED(const char* category_name)
-#define TRACE_EVENT_API_GET_CATEGORY_ENABLED \
-    webrtc::EventTracer::GetCategoryEnabled
-
-// Add a trace event to the platform tracing system.
-// void TRACE_EVENT_API_ADD_TRACE_EVENT(
-//                    char phase,
-//                    const unsigned char* category_enabled,
-//                    const char* name,
-//                    unsigned long long id,
-//                    int num_args,
-//                    const char** arg_names,
-//                    const unsigned char* arg_types,
-//                    const unsigned long long* arg_values,
-//                    unsigned char flags)
-#define TRACE_EVENT_API_ADD_TRACE_EVENT webrtc::EventTracer::AddTraceEvent
-
-////////////////////////////////////////////////////////////////////////////////
-
-// Implementation detail: trace event macros create temporary variables
-// to keep instrumentation overhead low. These macros give each temporary
-// variable a unique name based on the line number to prevent name collissions.
-#define INTERNAL_TRACE_EVENT_UID3(a,b) \
-    trace_event_unique_##a##b
-#define INTERNAL_TRACE_EVENT_UID2(a,b) \
-    INTERNAL_TRACE_EVENT_UID3(a,b)
-#define INTERNAL_TRACE_EVENT_UID(name_prefix) \
-    INTERNAL_TRACE_EVENT_UID2(name_prefix, __LINE__)
-
-// Implementation detail: internal macro to create static category.
-#define INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category) \
-    static const unsigned char* INTERNAL_TRACE_EVENT_UID(catstatic) = \
-        TRACE_EVENT_API_GET_CATEGORY_ENABLED(category);
-
-// Implementation detail: internal macro to create static category and add
-// event if the category is enabled.
-#define INTERNAL_TRACE_EVENT_ADD(phase, category, name, flags, ...) \
-    do { \
-      INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category); \
-      if (*INTERNAL_TRACE_EVENT_UID(catstatic)) { \
-        webrtc::trace_event_internal::AddTraceEvent(          \
-            phase, INTERNAL_TRACE_EVENT_UID(catstatic), name, \
-            webrtc::trace_event_internal::kNoEventId, flags, ##__VA_ARGS__); \
-      } \
-    } while (0)
-
-// Implementation detail: internal macro to create static category and add begin
-// event if the category is enabled. Also adds the end event when the scope
-// ends.
-#define INTERNAL_TRACE_EVENT_ADD_SCOPED(category, name, ...) \
-    INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category); \
-    webrtc::trace_event_internal::TraceEndOnScopeClose  \
-        INTERNAL_TRACE_EVENT_UID(profileScope); \
-    if (*INTERNAL_TRACE_EVENT_UID(catstatic)) { \
-      webrtc::trace_event_internal::AddTraceEvent(      \
-          TRACE_EVENT_PHASE_BEGIN, \
-          INTERNAL_TRACE_EVENT_UID(catstatic), \
-          name, webrtc::trace_event_internal::kNoEventId,       \
-          TRACE_EVENT_FLAG_NONE, ##__VA_ARGS__); \
-      INTERNAL_TRACE_EVENT_UID(profileScope).Initialize( \
-          INTERNAL_TRACE_EVENT_UID(catstatic), name); \
-    }
-
-// Implementation detail: internal macro to create static category and add
-// event if the category is enabled.
-#define INTERNAL_TRACE_EVENT_ADD_WITH_ID(phase, category, name, id, flags, \
-                                         ...) \
-    do { \
-      INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category); \
-      if (*INTERNAL_TRACE_EVENT_UID(catstatic)) { \
-        unsigned char trace_event_flags = flags | TRACE_EVENT_FLAG_HAS_ID; \
-        webrtc::trace_event_internal::TraceID trace_event_trace_id( \
-            id, &trace_event_flags); \
-        webrtc::trace_event_internal::AddTraceEvent( \
-            phase, INTERNAL_TRACE_EVENT_UID(catstatic), \
-            name, trace_event_trace_id.data(), trace_event_flags, \
-            ##__VA_ARGS__); \
-      } \
-    } while (0)
-
-// Notes regarding the following definitions:
-// New values can be added and propagated to third party libraries, but existing
-// definitions must never be changed, because third party libraries may use old
-// definitions.
-
-// Phase indicates the nature of an event entry. E.g. part of a begin/end pair.
-#define TRACE_EVENT_PHASE_BEGIN    ('B')
-#define TRACE_EVENT_PHASE_END      ('E')
-#define TRACE_EVENT_PHASE_INSTANT  ('I')
-#define TRACE_EVENT_PHASE_ASYNC_BEGIN ('S')
-#define TRACE_EVENT_PHASE_ASYNC_STEP  ('T')
-#define TRACE_EVENT_PHASE_ASYNC_END   ('F')
-#define TRACE_EVENT_PHASE_FLOW_BEGIN ('s')
-#define TRACE_EVENT_PHASE_FLOW_STEP  ('t')
-#define TRACE_EVENT_PHASE_FLOW_END   ('f')
-#define TRACE_EVENT_PHASE_METADATA ('M')
-#define TRACE_EVENT_PHASE_COUNTER  ('C')
-
-// Flags for changing the behavior of TRACE_EVENT_API_ADD_TRACE_EVENT.
-#define TRACE_EVENT_FLAG_NONE        (static_cast<unsigned char>(0))
-#define TRACE_EVENT_FLAG_COPY        (static_cast<unsigned char>(1 << 0))
-#define TRACE_EVENT_FLAG_HAS_ID      (static_cast<unsigned char>(1 << 1))
-#define TRACE_EVENT_FLAG_MANGLE_ID   (static_cast<unsigned char>(1 << 2))
-
-// Type values for identifying types in the TraceValue union.
-#define TRACE_VALUE_TYPE_BOOL         (static_cast<unsigned char>(1))
-#define TRACE_VALUE_TYPE_UINT         (static_cast<unsigned char>(2))
-#define TRACE_VALUE_TYPE_INT          (static_cast<unsigned char>(3))
-#define TRACE_VALUE_TYPE_DOUBLE       (static_cast<unsigned char>(4))
-#define TRACE_VALUE_TYPE_POINTER      (static_cast<unsigned char>(5))
-#define TRACE_VALUE_TYPE_STRING       (static_cast<unsigned char>(6))
-#define TRACE_VALUE_TYPE_COPY_STRING  (static_cast<unsigned char>(7))
-
-namespace webrtc {
-namespace trace_event_internal {
-
-// Specify these values when the corresponding argument of AddTraceEvent is not
-// used.
-const int kZeroNumArgs = 0;
-const unsigned long long kNoEventId = 0;
-
-// TraceID encapsulates an ID that can either be an integer or pointer. Pointers
-// are mangled with the Process ID so that they are unlikely to collide when the
-// same pointer is used on different processes.
-class TraceID {
- public:
-  class ForceMangle {
-    public:
-     explicit ForceMangle(unsigned long long id) : data_(id) {}
-     explicit ForceMangle(unsigned long id) : data_(id) {}
-     explicit ForceMangle(unsigned int id) : data_(id) {}
-     explicit ForceMangle(unsigned short id) : data_(id) {}
-     explicit ForceMangle(unsigned char id) : data_(id) {}
-     explicit ForceMangle(long long id)
-         : data_(static_cast<unsigned long long>(id)) {}
-     explicit ForceMangle(long id)
-         : data_(static_cast<unsigned long long>(id)) {}
-     explicit ForceMangle(int id)
-         : data_(static_cast<unsigned long long>(id)) {}
-     explicit ForceMangle(short id)
-         : data_(static_cast<unsigned long long>(id)) {}
-     explicit ForceMangle(signed char id)
-         : data_(static_cast<unsigned long long>(id)) {}
-
-     unsigned long long data() const { return data_; }
-
-    private:
-     unsigned long long data_;
-  };
-
-  explicit TraceID(const void* id, unsigned char* flags)
-      : data_(static_cast<unsigned long long>(
-              reinterpret_cast<uintptr_t>(id))) {
-    *flags |= TRACE_EVENT_FLAG_MANGLE_ID;
-  }
-  explicit TraceID(ForceMangle id, unsigned char* flags) : data_(id.data()) {
-    *flags |= TRACE_EVENT_FLAG_MANGLE_ID;
-  }
-  explicit TraceID(unsigned long long id, unsigned char* flags)
-      : data_(id) { (void)flags; }
-  explicit TraceID(unsigned long id, unsigned char* flags)
-      : data_(id) { (void)flags; }
-  explicit TraceID(unsigned int id, unsigned char* flags)
-      : data_(id) { (void)flags; }
-  explicit TraceID(unsigned short id, unsigned char* flags)
-      : data_(id) { (void)flags; }
-  explicit TraceID(unsigned char id, unsigned char* flags)
-      : data_(id) { (void)flags; }
-  explicit TraceID(long long id, unsigned char* flags)
-      : data_(static_cast<unsigned long long>(id)) { (void)flags; }
-  explicit TraceID(long id, unsigned char* flags)
-      : data_(static_cast<unsigned long long>(id)) { (void)flags; }
-  explicit TraceID(int id, unsigned char* flags)
-      : data_(static_cast<unsigned long long>(id)) { (void)flags; }
-  explicit TraceID(short id, unsigned char* flags)
-      : data_(static_cast<unsigned long long>(id)) { (void)flags; }
-  explicit TraceID(signed char id, unsigned char* flags)
-      : data_(static_cast<unsigned long long>(id)) { (void)flags; }
-
-  unsigned long long data() const { return data_; }
-
- private:
-  unsigned long long data_;
-};
-
-// Simple union to store various types as unsigned long long.
-union TraceValueUnion {
-  bool as_bool;
-  unsigned long long as_uint;
-  long long as_int;
-  double as_double;
-  const void* as_pointer;
-  const char* as_string;
-};
-
-// Simple container for const char* that should be copied instead of retained.
-class TraceStringWithCopy {
- public:
-  explicit TraceStringWithCopy(const char* str) : str_(str) {}
-  operator const char* () const { return str_; }
- private:
-  const char* str_;
-};
-
-// Define SetTraceValue for each allowed type. It stores the type and
-// value in the return arguments. This allows this API to avoid declaring any
-// structures so that it is portable to third_party libraries.
-#define INTERNAL_DECLARE_SET_TRACE_VALUE(actual_type, \
-                                         union_member, \
-                                         value_type_id) \
-    static inline void SetTraceValue(actual_type arg, \
-                                     unsigned char* type, \
-                                     unsigned long long* value) { \
-      TraceValueUnion type_value; \
-      type_value.union_member = arg; \
-      *type = value_type_id; \
-      *value = type_value.as_uint; \
-    }
-// Simpler form for int types that can be safely casted.
-#define INTERNAL_DECLARE_SET_TRACE_VALUE_INT(actual_type, \
-                                             value_type_id) \
-    static inline void SetTraceValue(actual_type arg, \
-                                     unsigned char* type, \
-                                     unsigned long long* value) { \
-      *type = value_type_id; \
-      *value = static_cast<unsigned long long>(arg); \
-    }
-
-INTERNAL_DECLARE_SET_TRACE_VALUE_INT(unsigned long long, TRACE_VALUE_TYPE_UINT)
-INTERNAL_DECLARE_SET_TRACE_VALUE_INT(unsigned long, TRACE_VALUE_TYPE_UINT)
-INTERNAL_DECLARE_SET_TRACE_VALUE_INT(unsigned int, TRACE_VALUE_TYPE_UINT)
-INTERNAL_DECLARE_SET_TRACE_VALUE_INT(unsigned short, TRACE_VALUE_TYPE_UINT)
-INTERNAL_DECLARE_SET_TRACE_VALUE_INT(unsigned char, TRACE_VALUE_TYPE_UINT)
-INTERNAL_DECLARE_SET_TRACE_VALUE_INT(long long, TRACE_VALUE_TYPE_INT)
-INTERNAL_DECLARE_SET_TRACE_VALUE_INT(long, TRACE_VALUE_TYPE_INT)
-INTERNAL_DECLARE_SET_TRACE_VALUE_INT(int, TRACE_VALUE_TYPE_INT)
-INTERNAL_DECLARE_SET_TRACE_VALUE_INT(short, TRACE_VALUE_TYPE_INT)
-INTERNAL_DECLARE_SET_TRACE_VALUE_INT(signed char, TRACE_VALUE_TYPE_INT)
-INTERNAL_DECLARE_SET_TRACE_VALUE(bool, as_bool, TRACE_VALUE_TYPE_BOOL)
-INTERNAL_DECLARE_SET_TRACE_VALUE(double, as_double, TRACE_VALUE_TYPE_DOUBLE)
-INTERNAL_DECLARE_SET_TRACE_VALUE(const void*, as_pointer,
-                                 TRACE_VALUE_TYPE_POINTER)
-INTERNAL_DECLARE_SET_TRACE_VALUE(const char*, as_string,
-                                 TRACE_VALUE_TYPE_STRING)
-INTERNAL_DECLARE_SET_TRACE_VALUE(const TraceStringWithCopy&, as_string,
-                                 TRACE_VALUE_TYPE_COPY_STRING)
-
-#undef INTERNAL_DECLARE_SET_TRACE_VALUE
-#undef INTERNAL_DECLARE_SET_TRACE_VALUE_INT
-
-// std::string version of SetTraceValue so that trace arguments can be strings.
-static inline void SetTraceValue(const std::string& arg,
-                                 unsigned char* type,
-                                 unsigned long long* value) {
-  TraceValueUnion type_value;
-  type_value.as_string = arg.c_str();
-  *type = TRACE_VALUE_TYPE_COPY_STRING;
-  *value = type_value.as_uint;
-}
-
-// These AddTraceEvent template functions are defined here instead of in the
-// macro, because the arg_values could be temporary objects, such as
-// std::string. In order to store pointers to the internal c_str and pass
-// through to the tracing API, the arg_values must live throughout
-// these procedures.
-
-static inline void AddTraceEvent(char phase,
-                                const unsigned char* category_enabled,
-                                const char* name,
-                                unsigned long long id,
-                                unsigned char flags) {
-  TRACE_EVENT_API_ADD_TRACE_EVENT(phase, category_enabled, name, id,
-                                  kZeroNumArgs, nullptr, nullptr, nullptr,
-                                  flags);
-}
-
-template<class ARG1_TYPE>
-static inline void AddTraceEvent(char phase,
-                                const unsigned char* category_enabled,
-                                const char* name,
-                                unsigned long long id,
-                                unsigned char flags,
-                                const char* arg1_name,
-                                const ARG1_TYPE& arg1_val) {
-  const int num_args = 1;
-  unsigned char arg_types[1];
-  unsigned long long arg_values[1];
-  SetTraceValue(arg1_val, &arg_types[0], &arg_values[0]);
-  TRACE_EVENT_API_ADD_TRACE_EVENT(
-      phase, category_enabled, name, id,
-      num_args, &arg1_name, arg_types, arg_values,
-      flags);
-}
-
-template<class ARG1_TYPE, class ARG2_TYPE>
-static inline void AddTraceEvent(char phase,
-                                const unsigned char* category_enabled,
-                                const char* name,
-                                unsigned long long id,
-                                unsigned char flags,
-                                const char* arg1_name,
-                                const ARG1_TYPE& arg1_val,
-                                const char* arg2_name,
-                                const ARG2_TYPE& arg2_val) {
-  const int num_args = 2;
-  const char* arg_names[2] = { arg1_name, arg2_name };
-  unsigned char arg_types[2];
-  unsigned long long arg_values[2];
-  SetTraceValue(arg1_val, &arg_types[0], &arg_values[0]);
-  SetTraceValue(arg2_val, &arg_types[1], &arg_values[1]);
-  TRACE_EVENT_API_ADD_TRACE_EVENT(
-      phase, category_enabled, name, id,
-      num_args, arg_names, arg_types, arg_values,
-      flags);
-}
-
-// Used by TRACE_EVENTx macro. Do not use directly.
-class TraceEndOnScopeClose {
- public:
-  // Note: members of data_ intentionally left uninitialized. See Initialize.
-  TraceEndOnScopeClose() : p_data_(nullptr) {}
-  ~TraceEndOnScopeClose() {
-    if (p_data_)
-      AddEventIfEnabled();
-  }
-
-  void Initialize(const unsigned char* category_enabled,
-                  const char* name) {
-    data_.category_enabled = category_enabled;
-    data_.name = name;
-    p_data_ = &data_;
-  }
-
- private:
-  // Add the end event if the category is still enabled.
-  void AddEventIfEnabled() {
-    // Only called when p_data_ is non-null.
-    if (*p_data_->category_enabled) {
-      TRACE_EVENT_API_ADD_TRACE_EVENT(TRACE_EVENT_PHASE_END,
-                                      p_data_->category_enabled, p_data_->name,
-                                      kNoEventId, kZeroNumArgs, nullptr,
-                                      nullptr, nullptr, TRACE_EVENT_FLAG_NONE);
-    }
-  }
-
-  // This Data struct workaround is to avoid initializing all the members
-  // in Data during construction of this object, since this object is always
-  // constructed, even when tracing is disabled. If the members of Data were
-  // members of this class instead, compiler warnings occur about potential
-  // uninitialized accesses.
-  struct Data {
-    const unsigned char* category_enabled;
-    const char* name;
-  };
-  Data* p_data_;
-  Data data_;
-};
-
-}  // namespace trace_event_internal
-}  // namespace webrtc
+// This header is deprecated and is just left here temporarily during
+// refactoring. See https://bugs.webrtc.org/7634 for more details.
+#include "webrtc/rtc_base/trace_event.h"
 
 #endif  // WEBRTC_BASE_TRACE_EVENT_H_