Standardize usage of virtual/override/final in remoting/

remoting/host/desktop_session_agent.h

Index: remoting/host/desktop_session_agent.h
diff --git a/remoting/host/desktop_session_agent.h b/remoting/host/desktop_session_agent.h
index 0aec84d3478fc06d72d6ceafaac28eec62046d09..e3c0b62dbd444893582acf198f2f31907ae00137 100644
--- a/remoting/host/desktop_session_agent.h
+++ b/remoting/host/desktop_session_agent.h
@@ -71,19 +71,18 @@ class DesktopSessionAgent
       scoped_refptr<AutoThreadTaskRunner> video_capture_task_runner);
 
   // IPC::Listener implementation.
-  virtual bool OnMessageReceived(const IPC::Message& message) override;
-  virtual void OnChannelConnected(int32 peer_pid) override;
-  virtual void OnChannelError() override;
+  bool OnMessageReceived(const IPC::Message& message) override;
+  void OnChannelConnected(int32 peer_pid) override;
+  void OnChannelError() override;
 
   // webrtc::DesktopCapturer::Callback implementation.
-  virtual webrtc::SharedMemory* CreateSharedMemory(size_t size) override;
-  virtual void OnCaptureCompleted(webrtc::DesktopFrame* frame) override;
+  webrtc::SharedMemory* CreateSharedMemory(size_t size) override;
+  void OnCaptureCompleted(webrtc::DesktopFrame* frame) override;
 
   // webrtc::MouseCursorMonitor::Callback implementation.
-  virtual void OnMouseCursor(webrtc::MouseCursor* cursor) override;
-  virtual void OnMouseCursorPosition(
-      webrtc::MouseCursorMonitor::CursorState state,
-      const webrtc::DesktopVector& position) override;
+  void OnMouseCursor(webrtc::MouseCursor* cursor) override;
+  void OnMouseCursorPosition(webrtc::MouseCursorMonitor::CursorState state,
+                             const webrtc::DesktopVector& position) override;
 
   // Forwards a local clipboard event though the IPC channel to the network
   // process.
@@ -104,15 +103,14 @@ class DesktopSessionAgent
  protected:
   friend class base::RefCountedThreadSafe<DesktopSessionAgent>;
 
-  virtual ~DesktopSessionAgent();
+  ~DesktopSessionAgent() override;
 
   // ClientSessionControl interface.
-  virtual const std::string& client_jid() const override;
-  virtual void DisconnectSession() override;
-  virtual void OnLocalMouseMoved(
-    const webrtc::DesktopVector& position) override;
-  virtual void SetDisableInputs(bool disable_inputs) override;
-  virtual void ResetVideoPipeline() override;
+  const std::string& client_jid() const override;
+  void DisconnectSession() override;
+  void OnLocalMouseMoved(const webrtc::DesktopVector& position) override;
+  void SetDisableInputs(bool disable_inputs) override;
+  void ResetVideoPipeline() override;
 
   // Handles StartSessionAgent request from the client.
   void OnStartSessionAgent(const std::string& authenticated_jid,