Replace URLDataSource::MessageLoopForRequestPath() with TaskRunnerForRequestPath().

chrome/browser/search/thumbnail_source.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/search/thumbnail_source.h"
 
 #include <stddef.h>
 
 #include "base/callback.h"
 #include "base/memory/ptr_util.h"
@@ skipping 61 matching lines @@
   if (page_url.is_valid() && capture_thumbnails_)
     thumbnail_service_->AddForcedURL(page_url);
 }
 
 std::string ThumbnailSource::GetMimeType(const std::string&) const {
   // We need to explicitly return a mime type, otherwise if the user tries to
   // drag the image they get no extension.
   return "image/png";
 }
 
-base::MessageLoop* ThumbnailSource::MessageLoopForRequestPath(
-    const std::string& path) const {
+scoped_refptr<base::SingleThreadTaskRunner>
+ThumbnailSource::TaskRunnerForRequestPath(const std::string& path) const {
   // TopSites can be accessed from the IO thread. Otherwise, the URLs should be
   // accessed on the UI thread.
   return thumbnail_service_.get()
              ? nullptr
-             : content::URLDataSource::MessageLoopForRequestPath(path);
+             : content::URLDataSource::TaskRunnerForRequestPath(path);
 }
 
 bool ThumbnailSource::ShouldServiceRequest(
     const net::URLRequest* request) const {
   if (request->url().SchemeIs(chrome::kChromeSearchScheme))
     return InstantIOContext::ShouldServiceRequest(request);
   return URLDataSource::ShouldServiceRequest(request);
 }
 
 void ThumbnailSource::ExtractPageAndThumbnailUrls(
@@ skipping 26 matching lines @@
   const SkBitmap* bitmap = image.ToSkBitmap();
   scoped_refptr<base::RefCountedBytes> encoded_data(
       new base::RefCountedBytes());
   if (!suggestions::EncodeSkBitmapToJPEG(*bitmap, &encoded_data->data())) {
     callback.Run(default_thumbnail_.get());
     return;
   }
 
   callback.Run(encoded_data.get());
 }