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

android_webview/common/aw_content_client.h

Index: android_webview/common/aw_content_client.h
diff --git a/android_webview/common/aw_content_client.h b/android_webview/common/aw_content_client.h
index 55a84e0941872da3ff90ae1d65fce69dc8554192..0a3a34308f54e2d43476c3c71ac680b1cbba314b 100644
--- a/android_webview/common/aw_content_client.h
+++ b/android_webview/common/aw_content_client.h
@@ -16,13 +16,13 @@ std::string GetUserAgent();
 class AwContentClient : public content::ContentClient {
  public:
   // ContentClient implementation.
-  virtual std::string GetProduct() const override;
-  virtual std::string GetUserAgent() const override;
-  virtual base::string16 GetLocalizedString(int message_id) const override;
-  virtual base::StringPiece GetDataResource(
+  std::string GetProduct() const override;
+  std::string GetUserAgent() const override;
+  base::string16 GetLocalizedString(int message_id) const override;
+  base::StringPiece GetDataResource(
       int resource_id,
       ui::ScaleFactor scale_factor) const override;
-  virtual bool CanSendWhileSwappedOut(const IPC::Message* message) override;
+  bool CanSendWhileSwappedOut(const IPC::Message* message) override;
 };
 
 }  // namespace android_webview