Use extensions::ResultCatcher; delete ExtensionApiTest::ResultCatcher.

extensions/test/result_catcher.h

Index: extensions/test/result_catcher.h
diff --git a/extensions/test/result_catcher.h b/extensions/test/result_catcher.h
index 43ebc27cc03b224b1541d5be4ca48729c82c9ffd..f389f85bc55773804487f4389a9d76bdba3e5a05 100644
--- a/extensions/test/result_catcher.h
+++ b/extensions/test/result_catcher.h
@@ -23,7 +23,6 @@ namespace extensions {
 // GetNextResult() and message() if GetNextResult() return false. If there
 // are no results, this method will pump the UI message loop until one is
 // received.
-// TODO(yoz): Replace the version in ExtensionApiTest with this.
 class ResultCatcher : public content::NotificationObserver {
  public:
   ResultCatcher();