Standardize usage of virtual/override/final in chrome/browser/media

chrome/browser/media/desktop_media_list_ash.h

Index: chrome/browser/media/desktop_media_list_ash.h
diff --git a/chrome/browser/media/desktop_media_list_ash.h b/chrome/browser/media/desktop_media_list_ash.h
index 2386026901c346a637739458ca5dd57715dc4895..2f35ea0a3748072cf1ddcc25da5297f3e33ab3bc 100644
--- a/chrome/browser/media/desktop_media_list_ash.h
+++ b/chrome/browser/media/desktop_media_list_ash.h
@@ -37,16 +37,15 @@ class DesktopMediaListAsh : public DesktopMediaList {
   };
 
   explicit DesktopMediaListAsh(int source_types);
-  virtual ~DesktopMediaListAsh();
+  ~DesktopMediaListAsh() override;
 
   // DesktopMediaList interface.
-  virtual void SetUpdatePeriod(base::TimeDelta period) override;
-  virtual void SetThumbnailSize(const gfx::Size& thumbnail_size) override;
-  virtual void StartUpdating(DesktopMediaListObserver* observer) override;
-  virtual int GetSourceCount() const override;
-  virtual const Source& GetSource(int index) const override;
-  virtual void SetViewDialogWindowId(
-      content::DesktopMediaID::Id dialog_id) override;
+  void SetUpdatePeriod(base::TimeDelta period) override;
+  void SetThumbnailSize(const gfx::Size& thumbnail_size) override;
+  void StartUpdating(DesktopMediaListObserver* observer) override;
+  int GetSourceCount() const override;
+  const Source& GetSource(int index) const override;
+  void SetViewDialogWindowId(content::DesktopMediaID::Id dialog_id) override;
 
  private:
   // Struct used to represent sources list the model gets from the Worker.