Add BackgroundModeOptimizer that can restart the browser

chrome/browser/background/background_mode_manager.h

 // 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.
 
 #ifndef CHROME_BROWSER_BACKGROUND_BACKGROUND_MODE_MANAGER_H_
 #define CHROME_BROWSER_BACKGROUND_BACKGROUND_MODE_MANAGER_H_
 
 #include <map>
+#include <memory>
 #include <set>
 #include <vector>
 
 #include "base/callback_forward.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/scoped_vector.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/background/background_application_list_model.h"
 #include "chrome/browser/lifetime/scoped_keep_alive.h"
 #include "chrome/browser/profiles/profile_attributes_storage.h"
 #include "chrome/browser/status_icons/status_icon.h"
 #include "chrome/browser/status_icons/status_icon_menu_model.h"
 #include "chrome/browser/ui/browser_list_observer.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "components/prefs/pref_change_registrar.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "extensions/common/extension.h"
 
+class BackgroundModeOptimizer;
 class BackgroundTrigger;
 class Browser;
 class PrefRegistrySimple;
 class Profile;
 class StatusIcon;
 class StatusTray;
 
 namespace base {
 class CommandLine;
 }
@@ skipping 41 matching lines @@
 
   // Suspends background mode until either ResumeBackgroundMode is called or
   // Chrome is restarted. This has the same effect as ending background mode
   // for the current browser session.
   virtual void SuspendBackgroundMode();
 
   // Resumes background mode. This ends a suspension of background mode, but
   // will not start it if it is not enabled.
   virtual void ResumeBackgroundMode();
 
+  // Invoked to take Chrome out of KeepAlive mode - chrome stops running in

[Bernhard Bauer, 2016/05/19 08:56:56]

Nit: capitalize "Chrome".

[dgn, 2016/06/20 17:45:18]

Done.

+  // the background and removes its status bar icon.
+  void EndBackgroundMode();

[sky, 2016/05/18 19:23:05]

Move implementation to match new position.

[dgn, 2016/06/20 17:45:18]

Made this private as it was before, introduced another method to replace it.

+
   // For testing purposes.
   int NumberOfBackgroundModeData();
 
   // Registers |trigger| as a reason for enabling background mode. Does not
   // take ownership of |profile| or |trigger|.
   void RegisterTrigger(Profile* profile,
                        BackgroundTrigger* trigger,
                        bool should_notify_user);
 
   // Unregisters |trigger| as a reason for enabling background mode.
@@ skipping 203 matching lines @@
   virtual void EnableLaunchOnStartup(bool should_launch);
 
   // Invoked when a client is installed so we can display a platform-specific
   // notification.
   virtual void DisplayClientInstalledNotification(const base::string16& name);
 
   // Invoked to put Chrome in KeepAlive mode - chrome runs in the background
   // and has a status bar icon.
   void StartBackgroundMode();
 
-  // Invoked to take Chrome out of KeepAlive mode - chrome stops running in
-  // the background and removes its status bar icon.
-  void EndBackgroundMode();
-
   // Enables keep alive and the status tray icon if and only if background mode
   // is active and not suspended.
   virtual void UpdateKeepAliveAndTrayIcon();
 
   // Release keep_alive_for_startup_. This is invoked as a callback to make
   // make sure the message queue was initialized before we attempt to exit.
   void ReleaseStartupKeepAliveCallback();
 
   // If --no-startup-window is passed, BackgroundModeManager will manually keep
   // chrome running while waiting for apps to load. This is called when we no
@@ skipping 93 matching lines @@
 
   // Background mode does not always keep Chrome alive. When it does, it is
   // using this scoped object.
   std::unique_ptr<ScopedKeepAlive> keep_alive_;
 
   // Set when we are keeping chrome running during the startup process - this
   // is required when running with the --no-startup-window flag, as otherwise
   // chrome would immediately exit due to having no open windows.
   std::unique_ptr<ScopedKeepAlive> keep_alive_for_startup_;
 
+  // Reference to the optimizer to use to reduce Chrome's footprint when in
+  // background mode. If null, optimizations are disabled.
+  std::unique_ptr<BackgroundModeOptimizer> optimizer_;
+
   // Set to true when Chrome is running with the --keep-alive-for-test flag
   // (used for testing background mode without having to install a background
   // app).
   bool keep_alive_for_test_;
 
   // Set to true when background mode is suspended.
   bool background_mode_suspended_;
 
   base::WeakPtrFactory<BackgroundModeManager> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BackgroundModeManager);
 };
 
 #endif  // CHROME_BROWSER_BACKGROUND_BACKGROUND_MODE_MANAGER_H_