Standardize usage of virtual/override/final in content/

content/child/npapi/np_channel_base.h

Index: content/child/npapi/np_channel_base.h
diff --git a/content/child/npapi/np_channel_base.h b/content/child/npapi/np_channel_base.h
index 6d70b6fdd91b268551a70e12ceeb5dd60aa0207f..d718936425fece594816ab5f54414afe710bb83f 100644
--- a/content/child/npapi/np_channel_base.h
+++ b/content/child/npapi/np_channel_base.h
@@ -55,7 +55,7 @@ class NPChannelBase : public IPC::Listener,
   int GetExistingRouteForNPObjectOwner(struct _NPP* owner);
 
   // IPC::Sender implementation:
-  virtual bool Send(IPC::Message* msg) override;
+  bool Send(IPC::Message* msg) override;
 
   base::ProcessId peer_pid() { return channel_->GetPeerPID(); }
   IPC::ChannelHandle channel_handle() const { return channel_handle_; }
@@ -92,7 +92,7 @@ class NPChannelBase : public IPC::Listener,
 
   friend class base::RefCountedThreadSafe<NPChannelBase>;
 
-  virtual ~NPChannelBase();
+  ~NPChannelBase() override;
 
   // Returns a NPChannelBase derived object for the given channel name.
   // If an existing channel exists returns that object, otherwise creates a
@@ -116,9 +116,9 @@ class NPChannelBase : public IPC::Listener,
   virtual bool OnControlMessageReceived(const IPC::Message& msg);
 
   // IPC::Listener implementation:
-  virtual bool OnMessageReceived(const IPC::Message& msg) override;
-  virtual void OnChannelConnected(int32 peer_pid) override;
-  virtual void OnChannelError() override;
+  bool OnMessageReceived(const IPC::Message& msg) override;
+  void OnChannelConnected(int32 peer_pid) override;
+  void OnChannelError() override;
 
   void set_send_unblocking_only_during_unblock_dispatch() {
     send_unblocking_only_during_unblock_dispatch_ = true;