Revert of Revert of Remove prefixed Pointer Lock API.

LayoutTests/pointer-lock/mouse-event-delivery-prefixed-expected.txt

-Test mouse events are routed to lock target.
-
-On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
-
-
-PASS document.onwebkitpointerlockchange event received.
-PASS document.webkitPointerLockElement is targetdiv1
-     With a lock in place send a click.
-PASS event type: mousedown, target: target1, received on: target1
-PASS event type: mousedown, target: target1, received on: body
-PASS document.onwebkitpointerlockchange event received.
-PASS document.webkitPointerLockElement is targetdiv2
-     With a lock in place send a click.
-PASS event type: mousedown, target: target2, received on: target2
-PASS event type: mousedown, target: target2, received on: body
-     Ensure double clicks work as expected, sending 4 clicks.
-     Creating a click and dblclick.
-PASS event type: mousedown, target: target2, received on: target2
-PASS event type: mouseup, target: target2, received on: target2
-PASS event type: click, target: target2, received on: target2
-PASS event type: mousedown, target: target2, received on: target2
-PASS event type: mouseup, target: target2, received on: target2
-PASS event type: click, target: target2, received on: target2
-PASS event type: dblclick, target: target2, received on: target2
-     Ensuring no false dblclicks if we continue.
-PASS event type: mousedown, target: target2, received on: target2
-PASS event type: mouseup, target: target2, received on: target2
-PASS event type: click, target: target2, received on: target2
-PASS event type: mousedown, target: target2, received on: target2
-PASS event type: mouseup, target: target2, received on: target2
-PASS event type: click, target: target2, received on: target2
-PASS successfullyParsed is true
-
-TEST COMPLETE
-