Sync HTML element interfaces S-V with the spec

Source/core/html/HTMLVideoElement.idl

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+// https://html.spec.whatwg.org/#the-video-element
+
 [
     RuntimeEnabled=Media
 ] interface HTMLVideoElement : HTMLMediaElement {
     [Reflect] attribute unsigned long width;
     [Reflect] attribute unsigned long height;
     readonly attribute unsigned long videoWidth;
     readonly attribute unsigned long videoHeight;
     [Reflect, URL] attribute DOMString poster;
 
+    // Non-standard APIs
     [RuntimeEnabled=PrefixedVideoFullscreen, DeprecateAs=PrefixedVideoSupportsFullscreen] readonly attribute boolean webkitSupportsFullscreen;
     [RuntimeEnabled=PrefixedVideoFullscreen, DeprecateAs=PrefixedVideoDisplayingFullscreen] readonly attribute boolean webkitDisplayingFullscreen;
 
     [RuntimeEnabled=PrefixedVideoFullscreen, DeprecateAs=PrefixedVideoEnterFullscreen, RaisesException, LogActivity, LogAllWorlds] void webkitEnterFullscreen();
     [RuntimeEnabled=PrefixedVideoFullscreen, DeprecateAs=PrefixedVideoExitFullscreen] void webkitExitFullscreen();
 
     // Note the different capitalization of the "S" in FullScreen.
     [RuntimeEnabled=PrefixedVideoFullscreen, DeprecateAs=PrefixedVideoEnterFullScreen, ImplementedAs=webkitEnterFullscreen, RaisesException, LogActivity, LogAllWorlds] void webkitEnterFullScreen();
     [RuntimeEnabled=PrefixedVideoFullscreen, DeprecateAs=PrefixedVideoExitFullScreen, ImplementedAs=webkitExitFullscreen] void webkitExitFullScreen();
 
     // The number of frames that have been decoded and made available for
     // playback.
     [MeasureAs=PrefixedVideoDecodedFrameCount] readonly attribute unsigned long webkitDecodedFrameCount;
 
     // The number of decoded frames that have been dropped by the player
     // for performance reasons during playback.
     [MeasureAs=PrefixedVideoDroppedFrameCount] readonly attribute unsigned long webkitDroppedFrameCount;
 };