Add the "virtual" keyword on method overrides that are missing it.

chrome/common/net/gaia/gaia_auth_fetcher.h

Index: chrome/common/net/gaia/gaia_auth_fetcher.h
diff --git a/chrome/common/net/gaia/gaia_auth_fetcher.h b/chrome/common/net/gaia/gaia_auth_fetcher.h
index e0fe76efac51c3f4aedafd284370a6e81abaf3ac..1a1602d55da7bbe8051801a9964564c17211e7b3 100644
--- a/chrome/common/net/gaia/gaia_auth_fetcher.h
+++ b/chrome/common/net/gaia/gaia_auth_fetcher.h
@@ -74,12 +74,12 @@ class GaiaAuthFetcher : public URLFetcher::Delegate {
                         const std::string& info_key);
 
   // Implementation of URLFetcher::Delegate
-  void OnURLFetchComplete(const URLFetcher* source,
-                          const GURL& url,
-                          const URLRequestStatus& status,
-                          int response_code,
-                          const ResponseCookies& cookies,
-                          const std::string& data);
+  virtual void OnURLFetchComplete(const URLFetcher* source,
+                                  const GURL& url,
+                                  const URLRequestStatus& status,
+                                  int response_code,
+                                  const ResponseCookies& cookies,
+                                  const std::string& data);
 
   // StartClientLogin been called && results not back yet?
   bool HasPendingFetch();