Move a few media controls elements into modules/media_controls/elements/.

third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.h

Index: third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.h
diff --git a/third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.h b/third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.h
index 3a24a5f16f461854fa224f03a158b223e49ed6c2..bf839b5f67ef1f5f8fc28653b7a0412e448017ba 100644
--- a/third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.h
+++ b/third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.h
@@ -38,6 +38,9 @@ class Event;
 class MediaControlsMediaEventListener;
 class MediaControlsOrientationLockDelegate;
 class MediaControlsWindowEventListener;
+class MediaControlMuteButtonElement;
+class MediaControlOverlayEnclosureElement;
+class MediaControlPanelEnclosureElement;
 class ShadowRoot;
 
 // Default implementation of the core/ MediaControls interface used by
@@ -96,7 +99,6 @@ class MODULES_EXPORT MediaControlsImpl final : public HTMLDivElement,
   // Called by the fullscreen buttons to toggle fulllscreen on/off.
   void EnterFullscreen() override;
   void ExitFullscreen() override;
-  void ShowOverlayCastButtonIfNeeded() override;
   void ToggleOverflowMenu() override;
   bool OverflowMenuVisible() override;
   // TODO(mlamouri): this method is needed in order to notify the controls that
@@ -107,6 +109,8 @@ class MODULES_EXPORT MediaControlsImpl final : public HTMLDivElement,
   }
   Document& OwnerDocument() { return GetDocument(); }
 
+  void ShowOverlayCastButtonIfNeeded();
+
   DECLARE_VIRTUAL_TRACE();
 
  private: