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

android_webview/renderer/aw_render_frame_ext.h

Index: android_webview/renderer/aw_render_frame_ext.h
diff --git a/android_webview/renderer/aw_render_frame_ext.h b/android_webview/renderer/aw_render_frame_ext.h
index 40141bc760f887d859ceff0053030b03c877a1f3..0643f7f872031a7a7be344bf4293c611091ac3f0 100644
--- a/android_webview/renderer/aw_render_frame_ext.h
+++ b/android_webview/renderer/aw_render_frame_ext.h
@@ -17,10 +17,10 @@ class AwRenderFrameExt : public content::RenderFrameObserver {
   AwRenderFrameExt(content::RenderFrame* render_frame);
 
  private:
-  virtual ~AwRenderFrameExt();
+  ~AwRenderFrameExt() override;
 
   // RenderFrame::Observer:
-  virtual void DidCommitProvisionalLoad(bool is_new_navigation) override;
+  void DidCommitProvisionalLoad(bool is_new_navigation) override;
   DISALLOW_COPY_AND_ASSIGN(AwRenderFrameExt);
 };