Use a direct include of the message_loop header in chrome/test/, chrome/tools/, chrome/utility/.

chrome/test/base/tracing.cc

 // 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.
 
 #include "chrome/test/base/tracing.h"
 
 #include "base/debug/trace_event.h"
 #include "base/memory/singleton.h"
-#include "base/message_loop.h"
+#include "base/message_loop/message_loop.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/trace_controller.h"
 #include "content/public/browser/trace_subscriber.h"
 #include "content/public/test/test_utils.h"
 
 namespace {
 
 using content::BrowserThread;
 
 class InProcessTraceController : public content::TraceSubscriber {
@@ skipping 131 matching lines @@
 bool WaitForWatchEvent(base::TimeDelta timeout) {
   return InProcessTraceController::GetInstance()->WaitForWatchEvent(timeout);
 }
 
 bool EndTracing(std::string* json_trace_output) {
   return InProcessTraceController::GetInstance()->EndTracing(json_trace_output);
 }
 
 }  // namespace tracing