Added GetCpuTime to base/ to get total CPU time consumed by process for perf tests.

webrtc/base/BUILD.gn

 # Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 import("//build/config/crypto.gni")
 import("//build/config/ui.gni")
@@ skipping 666 matching lines @@
       # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
       suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
     }
   }
 
   rtc_source_set("rtc_base_tests_utils") {
     testonly = true
     sources = [
       # Also use this as a convenient dumping ground for misc files that are
       # included by multiple targets below.
+      "cpu_time.cc",
+      "cpu_time.h",
       "fakeclock.cc",
       "fakeclock.h",
       "fakenetwork.h",
       "fakesslidentity.h",
       "firewallsocketserver.cc",
       "firewallsocketserver.h",
       "gunit.h",
       "httpserver.cc",
       "httpserver.h",
       "natserver.cc",
@@ skipping 61 matching lines @@
       "atomicops_unittest.cc",
       "base64_unittest.cc",
       "basictypes_unittest.cc",
       "bind_unittest.cc",
       "bitbuffer_unittest.cc",
       "buffer_unittest.cc",
       "bufferqueue_unittest.cc",
       "bytebuffer_unittest.cc",
       "byteorder_unittest.cc",
       "copyonwritebuffer_unittest.cc",
+      "cpu_time_unittest.cc",

[Taylor Brandstetter, 2017/02/17 23:35:47]

Sorry I didn't notice earlier, but this should go in rtc_base_nonparallel_tests.
These are tests that aren't run in parallel, so any tests based on real system
time or OS-level resources like sockets or files should use it. That hopefully
should fix the builtbot failures.

       "criticalsection_unittest.cc",
       "event_tracer_unittest.cc",
       "event_unittest.cc",
       "file_unittest.cc",
       "function_view_unittest.cc",
       "logging_unittest.cc",
       "md5digest_unittest.cc",
       "mod_ops_unittest.cc",
       "onetimeevent_unittest.cc",
       "optional_unittest.cc",
@@ skipping 122 matching lines @@
 
 if (is_android) {
   android_library("base_java") {
     java_files = [
       "java/src/org/webrtc/Logging.java",
       "java/src/org/webrtc/Size.java",
       "java/src/org/webrtc/ThreadUtils.java",
     ]
   }
 }