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

content/browser/media/capture/web_contents_video_capture_device.cc

Index: content/browser/media/capture/web_contents_video_capture_device.cc
diff --git a/content/browser/media/capture/web_contents_video_capture_device.cc b/content/browser/media/capture/web_contents_video_capture_device.cc
index 1d87f01097a518b2b397e32b370b74f9e2593d1a..2a10c94181a1a1fa30a4c38f8fd35275a73803f0 100644
--- a/content/browser/media/capture/web_contents_video_capture_device.cc
+++ b/content/browser/media/capture/web_contents_video_capture_device.cc
@@ -142,7 +142,7 @@ class FrameSubscriber : public RenderWidgetHostViewFrameSubscriber {
         oracle_proxy_(oracle),
         delivery_log_(delivery_log) {}
 
-  virtual bool ShouldCaptureFrame(
+  bool ShouldCaptureFrame(
       const gfx::Rect& damage_rect,
       base::TimeTicks present_time,
       scoped_refptr<media::VideoFrame>* storage,
@@ -185,12 +185,12 @@ class ContentCaptureSubscription : public content::NotificationObserver {
       const RenderWidgetHost& source,
       const scoped_refptr<ThreadSafeCaptureOracle>& oracle_proxy,
       const CaptureCallback& capture_callback);
-  virtual ~ContentCaptureSubscription();
+  ~ContentCaptureSubscription() override;
 
   // content::NotificationObserver implementation.
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) override;
+  void Observe(int type,
+               const content::NotificationSource& source,
+               const content::NotificationDetails& details) override;
 
  private:
   void OnTimer();
@@ -229,12 +229,12 @@ void RenderVideoFrame(const SkBitmap& input,
 class WebContentsCaptureMachine : public VideoCaptureMachine {
  public:
   WebContentsCaptureMachine(int render_process_id, int main_render_frame_id);
-  virtual ~WebContentsCaptureMachine();
+  ~WebContentsCaptureMachine() override;
 
   // VideoCaptureMachine overrides.
-  virtual bool Start(const scoped_refptr<ThreadSafeCaptureOracle>& oracle_proxy,
-                     const media::VideoCaptureParams& params) override;
-  virtual void Stop(const base::Closure& callback) override;
+  bool Start(const scoped_refptr<ThreadSafeCaptureOracle>& oracle_proxy,
+             const media::VideoCaptureParams& params) override;
+  void Stop(const base::Closure& callback) override;
 
   // Starts a copy from the backing store or the composited surface. Must be run
   // on the UI BrowserThread. |deliver_frame_cb| will be run when the operation