https://bugs.webkit.org/show_bug.cgi?id=88917

Reviewed by Dimitri Glazkov.

Source/WebCore:

Subsequent patches adding the new API for entering and exiting
pointer lock would be burdened by handling multiple change events
when the lock target is changed. This change introduces
temporary code to suppress duplicate change events.

Existing tests simplified by removing the duplicate change events.

* page/PointerLockController.cpp:
(WebCore::PointerLockController::requestPointerLock):
(WebCore::PointerLockController::didLosePointerLock):
* page/PointerLockController.h:
(PointerLockController):

LayoutTests:

Part of a series of refactoring changes to update pointer lock API to
the fullscreen locking style. https://bugs.webkit.org/show_bug.cgi?id=84402

Tests simplified by removing the duplicate change events.

* pointer-lock/lock-already-locked-expected.txt:
* pointer-lock/pointerlockchange-pointerlockerror-events-expected.txt:
* pointer-lock/pointerlockchange-pointerlockerror-events.html:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@120248 268f45cc-cd09-0410-ab3c-d52691b4dbfc