Create Document exitPointerLock and pointerLockElement API methods.

Source/core/dom/Document.idl

 /*
  * Copyright (C) 2006, 2007, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006, 2007 Samuel Weinig <sam@webkit.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 144 matching lines @@
 
     [MeasureAs=DocumentGetCSSCanvasContext] RenderingContext getCSSCanvasContext(DOMString contextId, DOMString name, long width, long height);
 
     // HTML 5
     HTMLCollection getElementsByClassName(DOMString classNames);
     readonly attribute Element activeElement;
     boolean hasFocus();
 
     readonly attribute DOMString compatMode;
 
     [MeasureAs=PrefixedDocumentExitPointerLock] void webkitExitPointerLock();

[Inactive, 2014/05/12 21:29:29]

We could use [ImplementedAs=exitPointerLock] and rename the method on native
side to avoid having both prefixed / unprefixed methods on native side.

[scheib, 2014/05/12 22:24:09]

Done.

+    [MeasureAs=DocumentExitPointerLock] void exitPointerLock();

[Inactive, 2014/05/12 21:29:29]

Why are we measuring the usage of the unprefixed ones?

[scheib, 2014/05/12 22:24:09]

To consider the eventual migration of usage from the prefixed version of the API
to unprefixed we should measure the prefixed:unprefixed ratio. The API is
critical to only a narrow application set, so we don't anticipate generally
large numbers.

     [MeasureAs=PrefixedDocumentPointerLockElement] readonly attribute Element webkitPointerLockElement;

[Inactive, 2014/05/12 21:29:29]

Ditto ([ImplementedAs]).

[scheib, 2014/05/12 22:24:09]

Done.

+    [MeasureAs=DocumentPointerLockElement] readonly attribute Element pointerLockElement;
 
     // Event handler attributes
     attribute EventHandler onbeforecopy;
     attribute EventHandler onbeforecut;
     attribute EventHandler onbeforepaste;
     attribute EventHandler oncopy;
     attribute EventHandler oncut;
     attribute EventHandler onpaste;
     attribute EventHandler onpointerlockchange;
     attribute EventHandler onpointerlockerror;
@@ skipping 39 matching lines @@
     // document in the console. It's possible http://crbug.com/43394 will resolve this.
     [MeasureAs=PrefixedPageVisibility, ImplementedAs=visibilityState] readonly attribute DOMString webkitVisibilityState;
     [MeasureAs=PrefixedPageVisibility, ImplementedAs=hidden] readonly attribute boolean webkitHidden;
 
     readonly attribute HTMLScriptElement currentScript;
 };
 
 Document implements GlobalEventHandlers;
 Document implements ParentNode;