<http://webkit.org/b/113836>
<rdar://problem/13587624>

Reviewed by Anders "Wesley Crusher" Carlsson.

Mac plugins expect flipped-Y screen coordinates, while DOM APIs speak in unflipped coordinates,
and we were mixing them up in the window frame caching optimization.

Solve this by having the UIProcess send both flipped and unflipped window frames to the WebProcess.
The flipped frame is passed on to plugins, and the unflipped frame is used for window.screenX/Y etc.

* UIProcess/API/mac/WKView.mm:
(-[WKView _updateWindowAndViewFrames]):

    No need to retrieve the window frame here as WebPageProxy::windowAndViewFramesChanged() will
    always override it anyway.

* UIProcess/mac/WebPageProxyMac.mm:
(WebKit::WebPageProxy::windowAndViewFramesChanged):
* WebProcess/WebCoreSupport/WebChromeClient.cpp:
(WebKit::WebChromeClient::windowRect):
* WebProcess/WebPage/WebPage.cpp:
(WebKit::WebPage::windowAndViewFramesChanged):
* WebProcess/WebPage/WebPage.h:
(WebKit::WebPage::windowFrameInUnflippedScreenCoordinates):
* WebProcess/WebPage/WebPage.messages.in:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148278 268f45cc-cd09-0410-ab3c-d52691b4dbfc