Standardize usage of virtual/override/final in content/

content/plugin/webplugin_delegate_stub.h

Index: content/plugin/webplugin_delegate_stub.h
diff --git a/content/plugin/webplugin_delegate_stub.h b/content/plugin/webplugin_delegate_stub.h
index 76584485049f27b21ae9f8b8db8026d1502641c2..d6f6323db1e108f1045b73b24a3ec27b2d41c582 100644
--- a/content/plugin/webplugin_delegate_stub.h
+++ b/content/plugin/webplugin_delegate_stub.h
@@ -42,10 +42,10 @@ class WebPluginDelegateStub : public IPC::Listener,
                         PluginChannel* channel);
 
   // IPC::Listener implementation:
-  virtual bool OnMessageReceived(const IPC::Message& msg) override;
+  bool OnMessageReceived(const IPC::Message& msg) override;
 
   // IPC::Sender implementation:
-  virtual bool Send(IPC::Message* msg) override;
+  bool Send(IPC::Message* msg) override;
 
   int instance_id() { return instance_id_; }
   WebPluginDelegateImpl* delegate() { return delegate_; }
@@ -54,7 +54,7 @@ class WebPluginDelegateStub : public IPC::Listener,
  private:
   friend class base::RefCounted<WebPluginDelegateStub>;
 
-  virtual ~WebPluginDelegateStub();
+  ~WebPluginDelegateStub() override;
 
   // Message handlers for the WebPluginDelegate calls that are proxied from the
   // renderer over the IPC channel.