Remove implicit conversions from scoped_refptr to T* in FileWatcher.

base/files/file_path_watcher.h

 // 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.
 
 // This module provides a way to monitor a file or directory for changes.
 
 #ifndef BASE_FILES_FILE_PATH_WATCHER_H_
 #define BASE_FILES_FILE_PATH_WATCHER_H_
 
 #include "base/base_export.h"
@@ skipping 44 matching lines @@
 
     // Stop watching. This is only called on the thread of the appropriate
     // message loop. Since it can also be called more than once, it should
     // check |is_cancelled()| to avoid duplicate work.
     virtual void CancelOnMessageLoopThread() = 0;
 
     scoped_refptr<base::MessageLoopProxy> message_loop() const {
       return message_loop_;
     }
 
-    void set_message_loop(base::MessageLoopProxy* loop) {
+    void set_message_loop(const scoped_refptr<base::MessageLoopProxy>& loop) {
       message_loop_ = loop;
     }
 
     // Must be called before the PlatformDelegate is deleted.
     void set_cancelled() {
       cancelled_ = true;
     }
 
     bool is_cancelled() const {
       return cancelled_;
@@ skipping 26 matching lines @@
 
  private:
   scoped_refptr<PlatformDelegate> impl_;
 
   DISALLOW_COPY_AND_ASSIGN(FilePathWatcher);
 };
 
 }  // namespace base
 
 #endif  // BASE_FILES_FILE_PATH_WATCHER_H_