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

content/public/test/test_download_request_handler.h

 // Copyright 2015 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 CONTENT_PUBLIC_TEST_TEST_DOWNLOAD_REQUEST_HANDLER_H_
 #define CONTENT_PUBLIC_TEST_TEST_DOWNLOAD_REQUEST_HANDLER_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 219 matching lines @@
   // Registers a request handler at the default URL. Call url() to determine the
   // URL.
   //
   // Notes:
   // * This constructor is only meant to be used for convenience when the caller
   //   is not interested in the URL used for interception. The URL used is
   //   generated at run time and should not be assumed to be the same across
   //   different runs of the same test.
   //
   // * Initialization of the handler synchronously runs a task on the
-  //   BrowserThread::IO thread using a nested message loop. Only construct an
+  //   BrowserThread::IO thread using a nested run loop. Only construct an
   //   instance of this object after browser threads have been initialized.
   TestDownloadRequestHandler();
 
   // Similar to the default constructor, but registers the handler at |url|.
   //
   // Notes:
   // * The behavior is undefined if more than one TestDownloadRequestHandler is
   //   registered for the same URL.
   TestDownloadRequestHandler(const GURL& url);
 
@@ skipping 67 matching lines @@
   class PartialResponseJob;
 
   GURL url_;
   base::WeakPtr<Interceptor> interceptor_;
   DISALLOW_COPY_AND_ASSIGN(TestDownloadRequestHandler);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_TEST_TEST_DOWNLOAD_REQUEST_HANDLER_H_