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

content/browser/renderer_host/gpu_message_filter.h

Index: content/browser/renderer_host/gpu_message_filter.h
diff --git a/content/browser/renderer_host/gpu_message_filter.h b/content/browser/renderer_host/gpu_message_filter.h
index d2f0acedb87e35deafe031aae754aaaccbe14415..57dfe9b45c3c7159b67a3a834b091d0cbd0563fa 100644
--- a/content/browser/renderer_host/gpu_message_filter.h
+++ b/content/browser/renderer_host/gpu_message_filter.h
@@ -37,7 +37,7 @@ class GpuMessageFilter : public BrowserMessageFilter {
                    RenderWidgetHelper* render_widget_helper);
 
   // BrowserMessageFilter methods:
-  virtual bool OnMessageReceived(const IPC::Message& message) override;
+  bool OnMessageReceived(const IPC::Message& message) override;
 
   // This set of API is used to subscribe to frame presentation events.
   // See RenderWidgetHostViewFrameSubscriber for more details.
@@ -52,7 +52,7 @@ class GpuMessageFilter : public BrowserMessageFilter {
   struct CreateViewCommandBufferRequest;
   struct FrameSubscription;
 
-  virtual ~GpuMessageFilter();
+  ~GpuMessageFilter() override;
 
   // Message handlers called on the browser IO thread:
   void OnEstablishGpuChannel(CauseForGpuLaunch,