Reland: Use a shared thread for media operations (round 3).

content/public/test/layouttest_support.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.
 
 #ifndef CONTENT_PUBLIC_TEST_LAYOUTTEST_SUPPORT_H_
 #define CONTENT_PUBLIC_TEST_LAYOUTTEST_SUPPORT_H_
 
 #include "base/callback_forward.h"
+#include "base/memory/ref_counted.h"
 
 namespace WebKit {
 class WebGamepads;
 struct WebSize;
 }
 
 namespace WebTestRunner {
 class WebTestProxyBase;
 }
 
+namespace base {
+class MessageLoopProxy;
+}
+
 namespace content {
 
 class RenderView;
 
 // Turn the browser process into layout test mode.
 void EnableBrowserLayoutTestMode();
 
 ///////////////////////////////////////////////////////////////////////////////
 // The following methods are meant to be used from a renderer.
 
@@ skipping 28 matching lines @@
 // Set the device scale factor and force the compositor to resize.
 void SetDeviceScaleFactor(RenderView* render_view, float factor);
 
 // Control auto resize mode.
 void EnableAutoResizeMode(RenderView* render_view,
                           const WebKit::WebSize& min_size,
                           const WebKit::WebSize& max_size);
 void DisableAutoResizeMode(RenderView* render_view,
                            const WebKit::WebSize& new_size);
 
+// Return the thread on which media operations should run.
+//
+// TODO(scherkus): We should be using RenderViewImpl::createMediaPlayer(), see
+// http://crbug.com/239826
+scoped_refptr<base::MessageLoopProxy> GetMediaThreadMessageLoopProxy();
+
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_TEST_LAYOUTTEST_SUPPORT_H_