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

chrome/browser/extensions/display_info_provider_mac.h

Index: chrome/browser/extensions/display_info_provider_mac.h
diff --git a/chrome/browser/extensions/display_info_provider_mac.h b/chrome/browser/extensions/display_info_provider_mac.h
index 59a919bc5d001b1e8b2266f813130b5f8449cddd..6795ef941369ab9e6c319e0b8ca6ebaf88f73ade 100644
--- a/chrome/browser/extensions/display_info_provider_mac.h
+++ b/chrome/browser/extensions/display_info_provider_mac.h
@@ -12,16 +12,16 @@ namespace extensions {
 class DisplayInfoProviderMac : public DisplayInfoProvider {
  public:
   DisplayInfoProviderMac();
-  virtual ~DisplayInfoProviderMac();
+  ~DisplayInfoProviderMac() override;
 
   // DisplayInfoProvider implementation.
-  virtual bool SetInfo(const std::string& display_id,
-                       const core_api::system_display::DisplayProperties& info,
-                       std::string* error) override;
-  virtual void UpdateDisplayUnitInfoForPlatform(
+  bool SetInfo(const std::string& display_id,
+               const core_api::system_display::DisplayProperties& info,
+               std::string* error) override;
+  void UpdateDisplayUnitInfoForPlatform(
       const gfx::Display& display,
       core_api::system_display::DisplayUnitInfo* unit) override;
-  virtual gfx::Screen* GetActiveScreen() override;
+  gfx::Screen* GetActiveScreen() override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DisplayInfoProviderMac);