replace OVERRIDE and FINAL with override and final in extensions/

extensions/common/manifest_handlers/background_info.h

Index: extensions/common/manifest_handlers/background_info.h
diff --git a/extensions/common/manifest_handlers/background_info.h b/extensions/common/manifest_handlers/background_info.h
index e9e360e696306160376a52b709ba8561c3bae2d7..cc96a1adc7da5db1b83dfc012023789cecf1b12d 100644
--- a/extensions/common/manifest_handlers/background_info.h
+++ b/extensions/common/manifest_handlers/background_info.h
@@ -83,14 +83,14 @@ class BackgroundManifestHandler : public ManifestHandler {
   BackgroundManifestHandler();
   virtual ~BackgroundManifestHandler();
 
-  virtual bool Parse(Extension* extension, base::string16* error) OVERRIDE;
+  virtual bool Parse(Extension* extension, base::string16* error) override;
   virtual bool Validate(const Extension* extension,
                         std::string* error,
-                        std::vector<InstallWarning>* warnings) const OVERRIDE;
-  virtual bool AlwaysParseForType(Manifest::Type type) const OVERRIDE;
+                        std::vector<InstallWarning>* warnings) const override;
+  virtual bool AlwaysParseForType(Manifest::Type type) const override;
 
  private:
-  virtual const std::vector<std::string> Keys() const OVERRIDE;
+  virtual const std::vector<std::string> Keys() const override;
 
   DISALLOW_COPY_AND_ASSIGN(BackgroundManifestHandler);
 };