[content/browser/media] Replace MessageLoopProxy usage with ThreadTaskRunnerHandle

content/browser/media/capture/web_contents_tracker.h

 // Copyright (c) 2013 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.
 //
 // Given a starting render_process_id and main_render_frame_id, the
 // WebContentsTracker tracks changes to the active RenderFrameHost tree during
 // the lifetime of a WebContents instance.  This is used when mirroring tab
 // video and audio so that user navigations, crashes, iframes, etc., during a
 // tab's lifetime allow the capturing code to remain active on the
 // current/latest render frame tree.
 //
 // Threading issues: Start(), Stop() and the ChangeCallback are invoked on the
 // same thread.  This can be any thread, and the decision is locked-in by
 // WebContentsTracker when Start() is called.
 
 #ifndef CONTENT_BROWSER_MEDIA_CAPTURE_WEB_CONTENTS_TRACKER_H_
 #define CONTENT_BROWSER_MEDIA_CAPTURE_WEB_CONTENTS_TRACKER_H_
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/web_contents_observer.h"
 
 namespace base {
-class MessageLoopProxy;
+class SingleThreadTaskRunner;
 }
 
 namespace content {
 
 class RenderWidgetHost;
 
 class CONTENT_EXPORT WebContentsTracker
     : public base::RefCountedThreadSafe<WebContentsTracker>,
       public WebContentsObserver {
  public:
@@ skipping 56 matching lines @@
 
   // WebContentsObserver overrides to notify the client that the capture target
   // may have changed due to a separate fullscreen widget shown/destroyed.
   void DidShowFullscreenWidget(int routing_id) override;
   void DidDestroyFullscreenWidget(int routing_id) override;
 
   // If true, the client is interested in the showing/destruction of fullscreen
   // RenderWidgetHosts.
   const bool track_fullscreen_rwh_;
 
-  // MessageLoop corresponding to the thread that called Start().
-  scoped_refptr<base::MessageLoopProxy> message_loop_;
+  // TaskRunner corresponding to the thread that called Start().
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   // Callback to run when the target RenderWidgetHost has changed.
   ChangeCallback callback_;
 
   // Pointer to the RenderWidgetHost provided in the last run of |callback_|.
   // This is used to eliminate duplicate callback runs.
   RenderWidgetHost* last_target_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsTracker);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_MEDIA_CAPTURE_WEB_CONTENTS_TRACKER_H_