Implement media cast buttons

Source/core/css/CSSPrimitiveValueMappings.h

 /*
  * Copyright (C) 2007 Alexey Proskuryakov <ap@nypop.com>.
  * Copyright (C) 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2009 Jeff Schiller <codedread@gmail.com>
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ skipping 431 matching lines @@
         break;
     case MediaOverlayPlayButtonPart:
         m_value.valueID = CSSValueMediaOverlayPlayButton;
         break;
     case MediaMuteButtonPart:
         m_value.valueID = CSSValueMediaMuteButton;
         break;
     case MediaToggleClosedCaptionsButtonPart:
         m_value.valueID = CSSValueMediaToggleClosedCaptionsButton;
         break;
+    case MediaCastOffButtonPart:
+        m_value.valueID = CSSValueInternalMediaCastOffButton;
+        break;
+    case MediaOverlayCastOffButtonPart:
+        m_value.valueID = CSSValueInternalMediaOverlayCastOffButton;
+        break;
     case MediaSliderPart:
         m_value.valueID = CSSValueMediaSlider;
         break;
     case MediaSliderThumbPart:
         m_value.valueID = CSSValueMediaSliderthumb;
         break;
     case MediaVolumeSliderContainerPart:
         m_value.valueID = CSSValueMediaVolumeSliderContainer;
         break;
     case MediaVolumeSliderPart:
@@ skipping 4381 matching lines @@
     default:
         break;
     }
     ASSERT_NOT_REACHED();
     return ScrollBehaviorInstant;
 }
 
 }
 
 #endif