Revert of Remove prefixed Pointer Lock API.

Source/core/dom/Document.idl

Index: Source/core/dom/Document.idl
diff --git a/Source/core/dom/Document.idl b/Source/core/dom/Document.idl
index 4a640c8fd6a07e09639c7a449d83b7bead584d22..c2f1c5f69a0973e2bbd7e066abc47e77e1114032 100644
--- a/Source/core/dom/Document.idl
+++ b/Source/core/dom/Document.idl
@@ -164,6 +164,8 @@
 
     [MeasureAs=DocumentExitPointerLock] void exitPointerLock();
     [MeasureAs=DocumentPointerLockElement] readonly attribute Element pointerLockElement;
+    [MeasureAs=PrefixedDocumentExitPointerLock, ImplementedAs=exitPointerLock] void webkitExitPointerLock();
+    [MeasureAs=PrefixedDocumentPointerLockElement, ImplementedAs=pointerLockElement] readonly attribute Element webkitPointerLockElement;
 
     // Event handler attributes
     attribute EventHandler onbeforecopy;
@@ -185,6 +187,8 @@
     [RuntimeEnabled=Touch] attribute EventHandler ontouchstart;
     attribute EventHandler onwebkitfullscreenchange;
     attribute EventHandler onwebkitfullscreenerror;
+    attribute EventHandler onwebkitpointerlockchange;
+    attribute EventHandler onwebkitpointerlockerror;
     attribute EventHandler onwheel;
 
     [RuntimeEnabled=Touch] Touch createTouch([Default=Undefined] optional Window window,