Make MediaSession a runtime-enabled feature on Desktop.

content/browser/media/session/media_session_uma_helper.h

 // Copyright 2015 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_BROWSER_MEDIA_ANDROID_MEDIA_SESSION_UMA_HELPER_H_
-#define CONTENT_BROWSER_MEDIA_ANDROID_MEDIA_SESSION_UMA_HELPER_H_
+#ifndef CONTENT_BROWSER_MEDIA_SESSION_MEDIA_SESSION_UMA_HELPER_H_
+#define CONTENT_BROWSER_MEDIA_SESSION_MEDIA_SESSION_UMA_HELPER_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "base/time/clock.h"
 #include "content/common/content_export.h"
 
 namespace base {
 class Clock;
 }  // base namespace
 
 namespace content {
@@ skipping 26 matching lines @@
   void SetClockForTest(scoped_ptr<base::Clock> testing_clock);
 
  private:
   base::TimeDelta total_active_time_;
   base::Time current_active_time_;
   scoped_ptr<base::Clock> clock_;
 };
 
 }  // namespace content
 
-#endif // CONTENT_BROWSER_MEDIA_ANDROID_MEDIA_SESSION_UMA_HELPER_H_
+#endif // CONTENT_BROWSER_MEDIA_SESSION_MEDIA_SESSION_UMA_HELPER_H_