[Metrics] Move ExternalMetrics ownership to ChromeBrowserMainPartsChromeos

chrome/browser/chromeos/chrome_browser_main_chromeos.cc

 // Copyright (c) 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 "chrome/browser/chromeos/chrome_browser_main_chromeos.h"
 
 #include <string>
 #include <vector>
 
 #include "ash/ash_switches.h"
@@ skipping 684 matching lines @@
   // available.
   idle_action_warning_observer_.reset(new IdleActionWarningObserver());
 
   ChromeBrowserMainPartsLinux::PostProfileInit();
 }
 
 void ChromeBrowserMainPartsChromeos::PreBrowserStart() {
   // -- This used to be in ChromeBrowserMainParts::PreMainMessageLoopRun()
   // -- just before MetricsService::LogNeedForCleanShutdown().
 
-  g_browser_process->metrics_service()->StartExternalMetrics();
+  // Start the external metrics service, which collects metrics from Chrome OS
+  // and passes them to the browser process.
+  external_metrics_ = new chromeos::ExternalMetrics;
+  external_metrics_->Start();
 
 #if defined(USE_X11)
   // Listen for system key events so that the user will be able to adjust the
   // volume on the login screen, if Chrome is running on Chrome OS
   // (i.e. not Linux desktop), and in non-test mode.
   // Note: SystemKeyEventListener depends on the DBus thread.
   if (base::SysInfo::IsRunningOnChromeOS() &&
       !parameters().ui_task) {  // ui_task is non-NULL when running tests.
     SystemKeyEventListener::Initialize();
   }
@@ skipping 141 matching lines @@
   // Destroy DBus services immediately after threads are stopped.
   dbus_services_.reset();
 
   ChromeBrowserMainPartsLinux::PostDestroyThreads();
 
   // Destroy DeviceSettingsService after g_browser_process.
   DeviceSettingsService::Shutdown();
 }
 
 }  //  namespace chromeos