[Background Sync] Use GcmNetworkManager to start the browser for sync events.

content/browser/android/background_sync_launcher_android.h

-// Copyright 2015 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 CONTENT_BROWSER_ANDROID_BACKGROUND_SYNC_LAUNCHER_ANDROID_H_
-#define CONTENT_BROWSER_ANDROID_BACKGROUND_SYNC_LAUNCHER_ANDROID_H_
-
-#include <set>
-
-#include "base/android/jni_android.h"
-#include "base/lazy_instance.h"
-#include "base/macros.h"
-#include "content/common/content_export.h"
-
-namespace content {
-
-class BackgroundSyncManager;
-
-// The BackgroundSyncLauncherAndroid singleton owns the Java
-// BackgroundSyncLauncher object and is used to register interest in starting
-// the browser the next time the device goes online. This class runs on the UI
-// thread.
-class CONTENT_EXPORT BackgroundSyncLauncherAndroid {
- public:
-  static BackgroundSyncLauncherAndroid* Get();
-
-  // Register the |registrant|'s interest (or disinterest) in starting the
-  // browser the next time the device goes online after the browser has closed.
-  // |registrant| is used to count the number of interested objects and is not
-  // accessed, therefore it is okay for |registrant| to be deleted before this
-  // class. Interest is reset the next time the BackgroundSyncLauncherAndroid is
-  // created (browser restart). The caller can remove interest in launching the
-  // browser by calling with |launch_when_next_online| set to false.
-  static void LaunchBrowserWhenNextOnline(
-      const BackgroundSyncManager* registrant,
-      bool launch_when_next_online);
-
-  static bool RegisterLauncher(JNIEnv* env);
-
- private:
-  friend struct base::DefaultLazyInstanceTraits<BackgroundSyncLauncherAndroid>;
-
-  // Constructor and destructor marked private to enforce singleton
-  BackgroundSyncLauncherAndroid();
-  ~BackgroundSyncLauncherAndroid();
-
-  void LaunchBrowserWhenNextOnlineImpl(const BackgroundSyncManager* registrant,
-                                       bool launch_when_next_online);
-
-  std::set<const BackgroundSyncManager*> launch_when_next_online_registrants_;
-  base::android::ScopedJavaGlobalRef<jobject> java_launcher_;
-  DISALLOW_COPY_AND_ASSIGN(BackgroundSyncLauncherAndroid);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_ANDROID_BACKGROUND_SYNC_LAUNCHER_ANDROID_H_