Magnifier: Prevent useless operation in enabling/disabling magnifier.

chrome/browser/chromeos/chrome_browser_main_chromeos.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/browser/chromeos/chrome_browser_main_chromeos.h"
 
 #include <string>
 #include <vector>
 
 #include "ash/shell.h"
@@ skipping 454 matching lines @@
         new default_app_order::ExternalLoader(false /* async */));
 
     UserManager::Get()->SessionStarted();
   }
 
   if (!app_order_loader_) {
     app_order_loader_.reset(
         new default_app_order::ExternalLoader(true /* async */));
   }
 
+  // Initialize magnification manager before ash tray is created. And this must
+  // be placed after UserManager::SessionStarted();
+  chromeos::MagnificationManager::Initialize();
+
   // In Aura builds this will initialize ash::Shell.
   ChromeBrowserMainPartsLinux::PreProfileInit();
 }
 
 void ChromeBrowserMainPartsChromeos::PostProfileInit() {
   // -- This used to be in ChromeBrowserMainParts::PreMainMessageLoopRun()
   // -- just after CreateProfile().
 
   policy::BrowserPolicyConnector* connector =
       g_browser_process->browser_policy_connector();
@@ skipping 35 matching lines @@
   // Initialize the brightness observer so that we'll display an onscreen
   // indication of brightness changes during login.
   brightness_observer_.reset(new BrightnessObserver());
   output_observer_.reset(new OutputObserver());
   resume_observer_.reset(new ResumeObserver());
   screen_lock_observer_.reset(new ScreenLockObserver());
   if (KioskModeSettings::Get()->IsKioskModeEnabled()) {
     power_state_override_ = new PowerStateOverride(
         PowerStateOverride::BLOCK_DISPLAY_SLEEP);
   }
-  magnification_manager_.reset(
-      chromeos::MagnificationManager::CreateInstance());
   chromeos::accessibility::Initialize();
 
   primary_display_switch_observer_.reset(
       new PrimaryDisplaySwitchObserver());
 
   removable_device_notifications_ =
       new RemovableDeviceNotificationsCros();
 
   // Initialize the network portal detector for Chrome OS. The network
   // portal detector starts to listen for notifications from
@@ skipping 78 matching lines @@
 
   // Tell DeviceSettingsService to stop talking to session_manager.
   DeviceSettingsService::Get()->Shutdown();
 
   // We should remove observers attached to D-Bus clients before
   // DBusThreadManager is shut down.
   screen_lock_observer_.reset();
   resume_observer_.reset();
   brightness_observer_.reset();
   output_observer_.reset();
-  magnification_manager_.reset();
   power_state_override_ = NULL;
 
   // The XInput2 event listener needs to be shut down earlier than when
   // Singletons are finally destroyed in AtExitManager.
   XInputHierarchyChangedEventListener::GetInstance()->Stop();
 
   // chromeos::SystemKeyEventListener::Shutdown() is always safe to call,
   // even if Initialize() wasn't called.
   SystemKeyEventListener::Shutdown();
   imageburner::BurnManager::Shutdown();
   AudioHandler::Shutdown();
 
   WebSocketProxyController::Shutdown();
 
   // Let classes unregister themselves as observers of the ash::Shell singleton
   // before the shell is destroyed.
   user_activity_notifier_.reset();
   video_activity_notifier_.reset();
   primary_display_switch_observer_.reset();
 
   // Detach D-Bus clients before DBusThreadManager is shut down.
   power_button_observer_.reset();
   screen_dimming_observer_.reset();
 
   // Delete ContactManager while |g_browser_process| is still alive.
   contact_manager_.reset();
 
+  chromeos::MagnificationManager::Shutdown();
+
   // Let the UserManager unregister itself as an observer of the CrosSettings
   // singleton before it is destroyed.
   UserManager::Get()->Shutdown();
 
   ChromeBrowserMainPartsLinux::PostMainMessageLoopRun();
 }
 
 void ChromeBrowserMainPartsChromeos::SetupPlatformFieldTrials() {
   SetupLowMemoryHeadroomFieldTrial();
 }
@@ skipping 38 matching lines @@
     } else if (trial->group() == margin_200mb) {
       LOG(WARNING) << "low_mem: Part of '200MB' experiment";
       LowMemoryObserver::SetLowMemoryMargin(200);
     } else {
       LOG(WARNING) << "low_mem: Part of 'default' experiment";
     }
   }
 }
 
 }  //  namespace chromeos