mash: Migrate MediaDelegate ownership and access to WmShell.

ash/common/media_delegate.h

Index: ash/common/media_delegate.h
diff --git a/ash/media_delegate.h b/ash/common/media_delegate.h
similarity index 88%
rename from ash/media_delegate.h
rename to ash/common/media_delegate.h
index 455be8395661065b6558ffba5a4f9a56f29cc318..1cc6cfc458175ac58ece9e79171750c660449e80 100644
--- a/ash/media_delegate.h
+++ b/ash/common/media_delegate.h
@@ -2,15 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef ASH_MEDIA_DELEGATE_H_
-#define ASH_MEDIA_DELEGATE_H_
+#ifndef ASH_COMMON_MEDIA_DELEGATE_H_
+#define ASH_COMMON_MEDIA_DELEGATE_H_
 
 #include "ash/common/session/session_types.h"
 
-namespace content {
-class BrowserContext;
-}
-
 namespace ash {
 
 enum MediaCaptureState {
@@ -41,4 +37,4 @@ class MediaDelegate {
 
 }  // namespace ash
 
-#endif  // ASH_MEDIA_DELEGATE_H_
+#endif  // ASH_COMMON_MEDIA_DELEGATE_H_