[Chromium] Allow asyncronous response of pointer lock requests in layout tests.

https://bugs.webkit.org/show_bug.cgi?id=95628

Reviewed by James Robinson.

Tools:

Future tests need the ability to respond asynchronously that
pointer lock requests have been accepted or rejected. This patch
adds the following:
    testRunner.setPointerLockWillRespondAsynchronously();
    testRunner.didAcquirePointerLock();
    testRunner.didNotAcquirePointerLock();

Tested in existing test:
    pointerlockchange-pointerlockerror-events.html

* DumpRenderTree/chromium/DRTTestRunner.cpp:
(DRTTestRunner::DRTTestRunner):
(DRTTestRunner::didAcquirePointerLock):
(DRTTestRunner::didNotAcquirePointerLock):
(DRTTestRunner::setPointerLockWillRespondAsynchronously):
* DumpRenderTree/chromium/DRTTestRunner.h:
(DRTTestRunner):
* DumpRenderTree/chromium/WebViewHost.cpp:
(WebViewHost::requestPointerLock):
(WebViewHost::didAcquirePointerLock):
(WebViewHost::didNotAcquirePointerLock):
* DumpRenderTree/chromium/WebViewHost.h:
(WebViewHost):
(WebViewHost::setPointerLockWillRespondAsynchronously):

LayoutTests:

Add testing for testRunner.setPointerLockWillRespondAsynchronously().

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

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@127473 268f45cc-cd09-0410-ab3c-d52691b4dbfc