Revert of [BackgroundSync] Trigger Background Sync events when Chrome is backgrounded on Android

content/browser/android/background_sync_network_observer_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_NETWORK_OBSERVER_ANDROID_H_
-#define CONTENT_BROWSER_ANDROID_BACKGROUND_SYNC_NETWORK_OBSERVER_ANDROID_H_
-
-#include "base/android/jni_android.h"
-#include "base/android/scoped_java_ref.h"
-#include "base/memory/weak_ptr.h"
-#include "content/browser/background_sync/background_sync_network_observer.h"
-#include "content/public/browser/browser_thread.h"
-
-namespace content {
-
-// BackgroundSyncNetworkObserverAndroid is a specialized
-// BackgroundSyncNetworkObserver which is backed by a NetworkChangeNotifier
-// that listens for network events even when the browser is paused, unlike the
-// standard NetworkChangeNotifier. This ensures that sync events can be fired
-// even when the browser is backgrounded, and other network observers are
-// disabled.
-class BackgroundSyncNetworkObserverAndroid
-    : public BackgroundSyncNetworkObserver {
- public:
-  // Creates a BackgroundSyncNetworkObserver. |network_changed_callback| is
-  // called via PostMessage when the network connection changes.
-  BackgroundSyncNetworkObserverAndroid(
-      const base::Closure& network_changed_callback);
-
-  ~BackgroundSyncNetworkObserverAndroid() override;
-
-  // This class lives on the UI thread and mediates all access to the Java
-  // BackgroundSyncNetworkObserver, which it creates and owns. It is in turn
-  // owned by the BackgroundSyncNetworkObserverAndroid.
-  class Observer : public base::RefCountedThreadSafe<
-                       BackgroundSyncNetworkObserverAndroid::Observer,
-                       content::BrowserThread::DeleteOnUIThread> {
-   public:
-    static scoped_refptr<BackgroundSyncNetworkObserverAndroid::Observer> Create(
-        base::Callback<void(net::NetworkChangeNotifier::ConnectionType)>
-            callback);
-
-    static bool RegisterNetworkObserver(JNIEnv* env);
-
-    // Called from BackgroundSyncNetworkObserver.java over JNI whenever the
-    // connection type changes. This updates the current connection type seen by
-    // this class and calls the |network_changed_callback| provided to the
-    // constructor, on the IO thread, with the new connection type.
-    void NotifyConnectionTypeChanged(JNIEnv* env,
-                                     jobject jcaller,
-                                     jint new_connection_type);
-
-   private:
-    friend struct BrowserThread::DeleteOnThread<BrowserThread::UI>;
-    friend class base::DeleteHelper<
-        BackgroundSyncNetworkObserverAndroid::Observer>;
-
-    Observer(base::Callback<void(net::NetworkChangeNotifier::ConnectionType)>
-                 callback);
-    void Init();
-    ~Observer();
-
-    // This callback is to be run on the IO thread whenever the connection type
-    // changes.
-    base::Callback<void(net::NetworkChangeNotifier::ConnectionType)> callback_;
-    base::android::ScopedJavaGlobalRef<jobject> j_observer_;
-
-    DISALLOW_COPY_AND_ASSIGN(Observer);
-  };
-
- private:
-  // Accessed on UI Thread
-  scoped_refptr<Observer> observer_;
-
-  base::WeakPtrFactory<BackgroundSyncNetworkObserverAndroid> weak_ptr_factory_;
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_ANDROID_BACKGROUND_SYNC_NETWORK_OBSERVER_ANDROID_H_