Update {virtual,override} to follow C++11 style in chrome.

chrome/renderer/tts_dispatcher.h

Index: chrome/renderer/tts_dispatcher.h
diff --git a/chrome/renderer/tts_dispatcher.h b/chrome/renderer/tts_dispatcher.h
index cc404037eb174d9f129e153b9b0129f80a73f5d5..8dea4c062f891a615205aafc4efe944e48793a7a 100644
--- a/chrome/renderer/tts_dispatcher.h
+++ b/chrome/renderer/tts_dispatcher.h
@@ -34,18 +34,17 @@ class TtsDispatcher
   explicit TtsDispatcher(blink::WebSpeechSynthesizerClient* client);
 
  private:
-  virtual ~TtsDispatcher();
+  ~TtsDispatcher() override;
 
   // RenderProcessObserver override.
   bool OnControlMessageReceived(const IPC::Message& message) override;
 
   // blink::WebSpeechSynthesizer implementation.
-  virtual void updateVoiceList() override;
-  virtual void speak(const blink::WebSpeechSynthesisUtterance& utterance)
-      override;
-  virtual void pause() override;
-  virtual void resume() override;
-  virtual void cancel() override;
+  void updateVoiceList() override;
+  void speak(const blink::WebSpeechSynthesisUtterance& utterance) override;
+  void pause() override;
+  void resume() override;
+  void cancel() override;
 
   blink::WebSpeechSynthesisUtterance FindUtterance(int utterance_id);