Use a direct include of the message_loop header in base/.

base/power_monitor/power_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/power_monitor/power_monitor.h"
 
-#include "base/message_loop.h"
+#include "base/message_loop/message_loop.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 
 class PowerTest : public PowerObserver {
  public:
   PowerTest()
       : power_state_changes_(0),
         suspends_(0),
         resumes_(0) {
@@ skipping 79 matching lines @@
   message_loop_.RunUntilIdle();
   EXPECT_EQ(test[0].resumes(), 1);
 
   // Send a duplicate resume notification.  This should be suppressed.
   ProcessPowerEvent(PowerMonitor::RESUME_EVENT);
   message_loop_.RunUntilIdle();
   EXPECT_EQ(test[0].resumes(), 1);
 }
 
 }  // namespace base