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

android_webview/renderer/aw_render_process_observer.h

Index: android_webview/renderer/aw_render_process_observer.h
diff --git a/android_webview/renderer/aw_render_process_observer.h b/android_webview/renderer/aw_render_process_observer.h
index 5c39787b73c8523040f14f841add869191975ebc..b2df85d78ed4cff6ca374e52cb2b0914a02c419b 100644
--- a/android_webview/renderer/aw_render_process_observer.h
+++ b/android_webview/renderer/aw_render_process_observer.h
@@ -16,11 +16,11 @@ namespace android_webview {
 class AwRenderProcessObserver : public content::RenderProcessObserver {
  public:
   AwRenderProcessObserver();
-  virtual ~AwRenderProcessObserver();
+  ~AwRenderProcessObserver() override;
 
   // content::RenderProcessObserver implementation.
-  virtual bool OnControlMessageReceived(const IPC::Message& message) override;
-  virtual void WebKitInitialized() override;
+  bool OnControlMessageReceived(const IPC::Message& message) override;
+  void WebKitInitialized() override;
 
  private:
   void OnClearCache();