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

content/renderer/gpu/queue_message_swap_promise.h

Index: content/renderer/gpu/queue_message_swap_promise.h
diff --git a/content/renderer/gpu/queue_message_swap_promise.h b/content/renderer/gpu/queue_message_swap_promise.h
index 0f4ea1d8450363cec52d34972a7fc735757b1dc7..4094b1b96ec7a41a3475525b5985b008602a67ed 100644
--- a/content/renderer/gpu/queue_message_swap_promise.h
+++ b/content/renderer/gpu/queue_message_swap_promise.h
@@ -23,13 +23,13 @@ class QueueMessageSwapPromise : public cc::SwapPromise {
                           scoped_refptr<FrameSwapMessageQueue> message_queue,
                           int source_frame_number);
 
-  virtual ~QueueMessageSwapPromise();
+  ~QueueMessageSwapPromise() override;
 
-  virtual void DidSwap(cc::CompositorFrameMetadata* metadata) override;
+  void DidSwap(cc::CompositorFrameMetadata* metadata) override;
 
-  virtual void DidNotSwap(DidNotSwapReason reason) override;
+  void DidNotSwap(DidNotSwapReason reason) override;
 
-  virtual int64 TraceId() const override;
+  int64 TraceId() const override;
 
  private:
   void PromiseCompleted();