Standardize usage of virtual/override/final in remoting/

remoting/protocol/clipboard_thread_proxy.h

Index: remoting/protocol/clipboard_thread_proxy.h
diff --git a/remoting/protocol/clipboard_thread_proxy.h b/remoting/protocol/clipboard_thread_proxy.h
index ba63981dd0246729f21433c9ab5a839b8ed43fd7..af688320dd9c8deebfe229be58630bb6d82b22ec 100644
--- a/remoting/protocol/clipboard_thread_proxy.h
+++ b/remoting/protocol/clipboard_thread_proxy.h
@@ -21,7 +21,7 @@ namespace protocol {
 
 class ClipboardThreadProxy : public ClipboardStub {
  public:
-  virtual ~ClipboardThreadProxy();
+  ~ClipboardThreadProxy() override;
 
   // Constructs a proxy for |clipboard_stub| which will trampoline invocations
   // to |clipboard_stub_task_runner|.
@@ -30,7 +30,7 @@ class ClipboardThreadProxy : public ClipboardStub {
       scoped_refptr<base::TaskRunner> clipboard_stub_task_runner);
 
   // ClipboardStub implementation.
-  virtual void InjectClipboardEvent(const ClipboardEvent& event) override;
+  void InjectClipboardEvent(const ClipboardEvent& event) override;
 
  private:
   // Injects a clipboard event into a stub, if the given weak pointer to the