Add OVERRIDE to chrome/browser/extensions/.

chrome/browser/extensions/extension_webrequest_api.h

Index: chrome/browser/extensions/extension_webrequest_api.h
diff --git a/chrome/browser/extensions/extension_webrequest_api.h b/chrome/browser/extensions/extension_webrequest_api.h
index 400d46a7534ddbe3c9b32728cfb39f717d78a5ea..cc2b05e7a44e0f22b605b37d00f6b515ac64cb45 100644
--- a/chrome/browser/extensions/extension_webrequest_api.h
+++ b/chrome/browser/extensions/extension_webrequest_api.h
@@ -342,19 +342,19 @@ class ExtensionWebRequestEventRouter {
 
 class WebRequestAddEventListener : public SyncIOThreadExtensionFunction {
  public:
-  virtual bool RunImpl();
+  virtual bool RunImpl() OVERRIDE;
   DECLARE_EXTENSION_FUNCTION_NAME("experimental.webRequest.addEventListener");
 };
 
 class WebRequestEventHandled : public SyncIOThreadExtensionFunction {
  public:
-  virtual bool RunImpl();
+  virtual bool RunImpl() OVERRIDE;
   DECLARE_EXTENSION_FUNCTION_NAME("experimental.webRequest.eventHandled");
 };
 
 class WebRequestHandlerBehaviorChanged : public SyncIOThreadExtensionFunction {
  public:
-  virtual bool RunImpl();
+  virtual bool RunImpl() OVERRIDE;
   DECLARE_EXTENSION_FUNCTION_NAME(
       "experimental.webRequest.handlerBehaviorChanged");