Revert of base: Remove use of MessageLoopProxy

base/trace_event/trace_event_system_stats_monitor_unittest.cc

 // Copyright 2013 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.
 
 #include "base/trace_event/trace_event_system_stats_monitor.h"
 
 #include <sstream>
 #include <string>
 
+#include "base/message_loop/message_loop.h"
 #include "base/trace_event/trace_event_impl.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 namespace trace_event {
 
 #if !defined(OS_IOS)
 // Tests for the system stats monitor.
 // Exists as a class so it can be a friend of TraceEventSystemStatsMonitor.
 class TraceSystemStatsMonitorTest : public testing::Test {
  public:
   TraceSystemStatsMonitorTest() {}
   ~TraceSystemStatsMonitorTest() override {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TraceSystemStatsMonitorTest);
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 TEST_F(TraceSystemStatsMonitorTest, TraceEventSystemStatsMonitor) {
   MessageLoop message_loop;
 
   // Start with no observers of the TraceLog.
   EXPECT_EQ(0u, TraceLog::GetInstance()->GetObserverCountForTest());
 
   // Creating a system stats monitor adds it to the TraceLog observer list.
   scoped_ptr<TraceEventSystemStatsMonitor> system_stats_monitor(
-      new TraceEventSystemStatsMonitor(message_loop.task_runner()));
+      new TraceEventSystemStatsMonitor(
+          message_loop.message_loop_proxy()));
   EXPECT_EQ(1u, TraceLog::GetInstance()->GetObserverCountForTest());
   EXPECT_TRUE(
       TraceLog::GetInstance()->HasEnabledStateObserver(
           system_stats_monitor.get()));
 
   // By default the observer isn't dumping memory profiles.
   EXPECT_FALSE(system_stats_monitor->IsTimerRunningForTest());
 
   // Simulate enabling tracing.
   system_stats_monitor->StartProfiling();
   message_loop.RunUntilIdle();
   EXPECT_TRUE(system_stats_monitor->IsTimerRunningForTest());
 
   // Simulate disabling tracing.
   system_stats_monitor->StopProfiling();
   message_loop.RunUntilIdle();
   EXPECT_FALSE(system_stats_monitor->IsTimerRunningForTest());
 
   // Deleting the observer removes it from the TraceLog observer list.
   system_stats_monitor.reset();
   EXPECT_EQ(0u, TraceLog::GetInstance()->GetObserverCountForTest());
 }
 #endif  // !defined(OS_IOS)
 
 }  // namespace trace_event
 }  // namespace base