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 89 matching lines @@
     "bufferqueue.cc",
     "bufferqueue.h",
     "bytebuffer.cc",
     "bytebuffer.h",
     "byteorder.h",
     "checks.cc",
     "checks.h",
     "constructormagic.h",
     "copyonwritebuffer.cc",
     "copyonwritebuffer.h",
+    "cpu_time.cc",
+    "cpu_time.h",
     "criticalsection.cc",
     "criticalsection.h",
     "deprecation.h",
     "event.cc",
     "event.h",
     "event_tracer.cc",
     "event_tracer.h",
     "file.cc",
     "file.h",
     "flags.cc",
@@ skipping 600 matching lines @@
 
     if (!build_with_chromium && is_clang) {
       # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
       suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
     }
   }
 
   rtc_source_set("rtc_base_nonparallel_tests") {
     testonly = true
     sources = [
+      "cpu_time_unittest.cc",
       "nullsocketserver_unittest.cc",
       "physicalsocketserver_unittest.cc",
       "socket_unittest.cc",
       "socket_unittest.h",
       "socketaddress_unittest.cc",
       "virtualsocket_unittest.cc",
     ]
     deps = [
       ":rtc_base",
       ":rtc_base_tests_main",
@@ skipping 158 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",
     ]
   }
 }