Standardize usage of virtual/override/final in content/browser/

content/browser/frame_host/render_frame_host_impl.cc

Index: content/browser/frame_host/render_frame_host_impl.cc
diff --git a/content/browser/frame_host/render_frame_host_impl.cc b/content/browser/frame_host/render_frame_host_impl.cc
index e4f174e0a9bf2b8ada160b9f94fc5e0e178f226c..bd837fae08130bbbc8718b4fc24b8a689fbbdc46 100644
--- a/content/browser/frame_host/render_frame_host_impl.cc
+++ b/content/browser/frame_host/render_frame_host_impl.cc
@@ -85,9 +85,9 @@ class DesktopNotificationDelegateImpl : public DesktopNotificationDelegate {
         render_frame_id_(render_frame_host->GetRoutingID()),
         notification_id_(notification_id) {}
 
-  virtual ~DesktopNotificationDelegateImpl() {}
+  ~DesktopNotificationDelegateImpl() override {}
 
-  virtual void NotificationDisplayed() override {
+  void NotificationDisplayed() override {
     RenderFrameHost* rfh =
         RenderFrameHost::FromID(render_process_id_, render_frame_id_);
     if (!rfh)
@@ -97,7 +97,7 @@ class DesktopNotificationDelegateImpl : public DesktopNotificationDelegate {
         rfh->GetRoutingID(), notification_id_));
   }
 
-  virtual void NotificationError() override {
+  void NotificationError() override {
     RenderFrameHost* rfh =
         RenderFrameHost::FromID(render_process_id_, render_frame_id_);
     if (!rfh)
@@ -107,7 +107,7 @@ class DesktopNotificationDelegateImpl : public DesktopNotificationDelegate {
         rfh->GetRoutingID(), notification_id_));
   }
 
-  virtual void NotificationClosed(bool by_user) override {
+  void NotificationClosed(bool by_user) override {
     RenderFrameHost* rfh =
         RenderFrameHost::FromID(render_process_id_, render_frame_id_);
     if (!rfh)
@@ -119,7 +119,7 @@ class DesktopNotificationDelegateImpl : public DesktopNotificationDelegate {
         notification_id_);
   }
 
-  virtual void NotificationClick() override {
+  void NotificationClick() override {
     RenderFrameHost* rfh =
         RenderFrameHost::FromID(render_process_id_, render_frame_id_);
     if (!rfh)