Remove implicit conversions from scoped_refptr to T* in chrome/browser/media_galleries/

chrome/browser/media_galleries/media_folder_finder.cc

 // 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.
 
 #include "chrome/browser/media_galleries/media_folder_finder.h"
 
 #include <algorithm>
 #include <set>
 
 #include "base/files/file_enumerator.h"
@@ skipping 399 matching lines @@
 
   if (folders_to_scan_.empty()) {
     scan_state_ = SCAN_STATE_FINISHED;
     results_callback_.Run(true /* success? */, results_);
     return;
   }
 
   base::FilePath folder_to_scan = folders_to_scan_.back();
   folders_to_scan_.pop_back();
   base::PostTaskAndReplyWithResult(
-      worker_task_runner_, FROM_HERE,
-      base::Bind(&Worker::ScanFolder,
-                 base::Unretained(worker_),
-                 folder_to_scan),
+      worker_task_runner_.get(),
+      FROM_HERE,
+      base::Bind(
+          &Worker::ScanFolder, base::Unretained(worker_), folder_to_scan),
       base::Bind(&MediaFolderFinder::GotScanResults,
                  weak_factory_.GetWeakPtr(),
                  folder_to_scan));
 }
 
 void MediaFolderFinder::GotScanResults(const base::FilePath& path,
                                        const WorkerReply& reply) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   DCHECK_EQ(SCAN_STATE_STARTED, scan_state_);
   DCHECK(!path.empty());
   CHECK(!ContainsKey(results_, path));
 
   if (!IsEmptyScanResult(reply.scan_result))
     results_[path] = reply.scan_result;
 
   // Push new folders to the |folders_to_scan_| in reverse order.
   std::copy(reply.new_folders.rbegin(), reply.new_folders.rend(),
             std::back_inserter(folders_to_scan_));
 
   ScanFolder();
 }