Refactor code listening to platform events in content/renderer/.

content/renderer/battery_status/battery_status_dispatcher.h

 // Copyright 2014 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_RENDERER_BATTERY_STATUS_BATTERY_STATUS_DISPATCHER_H_
 #define CONTENT_RENDERER_BATTERY_STATUS_BATTERY_STATUS_DISPATCHER_H_
 
-#include "content/public/renderer/render_process_observer.h"
+#include "content/public/renderer/platform_event_observer.h"
 
 namespace blink {
 class WebBatteryStatus;
 class WebBatteryStatusListener;
 }
 
 namespace content {
 class RenderThread;
 
-class CONTENT_EXPORT BatteryStatusDispatcher : public RenderProcessObserver {
+class CONTENT_EXPORT BatteryStatusDispatcher
+    : NON_EXPORTED_BASE(
+          public PlatformEventObserver<blink::WebBatteryStatusListener>) {
  public:
   explicit BatteryStatusDispatcher(RenderThread* thread);
   virtual ~BatteryStatusDispatcher();
 
-  // RenderProcessObserver method.
+  // PlatformEventObserver public methods.
   virtual bool OnControlMessageReceived(const IPC::Message& message) OVERRIDE;
-
-  // Sets the listener to receive battery status updates. Returns true if the
-  // registration was successful.
-  bool SetListener(blink::WebBatteryStatusListener* listener);
+  virtual void SendFakeDataForTesting(void* data) OVERRIDE;
 
  protected:
-  virtual bool Start();
-  virtual bool Stop();
+  // PlatformEventObserver protected methods.
+  virtual void SendStartMessage() OVERRIDE;
+  virtual void SendStopMessage() OVERRIDE;
 
  private:
   void OnDidChange(const blink::WebBatteryStatus& status);
 
-  blink::WebBatteryStatusListener* listener_;
-
   DISALLOW_COPY_AND_ASSIGN(BatteryStatusDispatcher);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_BATTERY_STATUS_BATTERY_STATUS_DISPATCHER_H_