Replace "nested message loop" with "nested run loop" in comments.

extensions/test/result_catcher.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef EXTENSIONS_TEST_RESULT_CATCHER_H_
 #define EXTENSIONS_TEST_RESULT_CATCHER_H_
 
 #include <deque>
 #include <string>
 
@@ skipping 39 matching lines @@
   // A sequential list of pass/fail notifications from the test extension(s).
   std::deque<bool> results_;
 
   // If it failed, what was the error message?
   std::deque<std::string> messages_;
   std::string message_;
 
   // If non-NULL, we will listen to events from this BrowserContext only.
   content::BrowserContext* browser_context_restriction_;
 
-  // Only set if we're in a nested message loop waiting for results from
+  // Only set if we're in a nested run loop waiting for results from
   // the extension.
   base::Closure quit_closure_;
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_TEST_RESULT_CATCHER_H_