Replace NULL with nullptr or null in webrtc/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>
 
@@ skipping 802 matching lines @@
 // 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, NULL, NULL, NULL,
-      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) {
@@ skipping 26 matching lines @@
   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_(NULL) {}
+  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, NULL, NULL, NULL,
-          TRACE_EVENT_FLAG_NONE);
+      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
 
 #endif  // WEBRTC_BASE_TRACE_EVENT_H_