Let the effective media volume be 0 if the media element is muted

Source/core/testing/Internals.idl

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 187 matching lines @@
     DOMString[] allIconURLs(Document document);
     long numberOfPages(optional double pageWidthInPixels, optional double pageHeightInPixels);
     [RaisesException] DOMString pageProperty(DOMString propertyName, long pageNumber);
     [RaisesException] DOMString pageSizeAndMarginsInPixels(long pageIndex, long width, long height, long marginTop, long marginRight, long marginBottom, long marginLeft);
 
     [RaisesException] void setDeviceScaleFactor(float scaleFactor);
 
     [RaisesException, TypeChecking=Interface] void setIsCursorVisible(Document document, boolean isVisible);
 
     void mediaPlayerRequestFullscreen(HTMLMediaElement mediaElement);
+    double effectiveMediaVolume(HTMLMediaElement mediaElement);
 
     void registerURLSchemeAsBypassingContentSecurityPolicy(DOMString scheme);
     void removeURLSchemeRegisteredAsBypassingContentSecurityPolicy(DOMString scheme);
 
     TypeConversions typeConversions();
 
     // This is enabled only in Debug builds.
     // This is because we want to avoid putting the byte stream of testing private scripts
     // into the binary of Release builds.
     PrivateScriptTest privateScriptTest();
@@ skipping 59 matching lines @@
     // These functions are for testing NetInfo. You must call setNetworkStateNotifierTestOnly(true)
     // before calling setNetworkConnectionInfo.
     void setNetworkStateNotifierTestOnly(boolean testOnly);
     [RaisesException] void setNetworkConnectionInfo(DOMString type);
 
     // This function is for testing HitRegions on Canvas2D.
     unsigned long countHitRegions(CanvasRenderingContext2D context);
 
     DOMString serializeNavigationMarkup(Document document);
 };