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

content/browser/devtools/devtools_frontend_host_impl.h

Index: content/browser/devtools/devtools_frontend_host_impl.h
diff --git a/content/browser/devtools/devtools_frontend_host_impl.h b/content/browser/devtools/devtools_frontend_host_impl.h
index 66e65b786bbf21a423db89e3fc0c0d1582db982d..98b907497a1fb34920755539568cc02f0ec86da5 100644
--- a/content/browser/devtools/devtools_frontend_host_impl.h
+++ b/content/browser/devtools/devtools_frontend_host_impl.h
@@ -15,11 +15,11 @@ class DevToolsFrontendHostImpl : public DevToolsFrontendHost,
  public:
   DevToolsFrontendHostImpl(RenderViewHost* frontend_rvh,
                            DevToolsFrontendHost::Delegate* delegate);
-  virtual ~DevToolsFrontendHostImpl();
+  ~DevToolsFrontendHostImpl() override;
 
  private:
   // WebContentsObserver overrides.
-  virtual bool OnMessageReceived(const IPC::Message& message) override;
+  bool OnMessageReceived(const IPC::Message& message) override;
 
   void OnDispatchOnInspectorBackend(const std::string& message);
   void OnDispatchOnEmbedder(const std::string& message);