Reviewed by Adam Roben.

        Assertion failure in DrawingAreaImpl::display when calling WKPageForceRepaint on a page that uses accelerated compositing
        https://bugs.webkit.org/show_bug.cgi?id=54575
        <rdar://problem/8979594>

        Add test.
        * TestWebKitAPI/TestWebKitAPI.xcodeproj/project.pbxproj:
        * TestWebKitAPI/Tests/WebKit2/ForceRepaint.cpp: Added.
        (TestWebKitAPI::didForceRepaint):
        (TestWebKitAPI::didFinishLoadForFrame):
        (TestWebKitAPI::TEST):
        * TestWebKitAPI/Tests/WebKit2/simple-accelerated-compositing.html: Added.
        * TestWebKitAPI/win/TestWebKitAPI.vcproj:
        * TestWebKitAPI/win/copy-resources.cmd:
2011-02-16  Anders Carlsson  <andersca@apple.com>

        Reviewed by Adam Roben.

        Assertion failure in DrawingAreaImpl::display when calling WKPageForceRepaint on a page that uses accelerated compositing
        https://bugs.webkit.org/show_bug.cgi?id=54575
        <rdar://problem/8979594>

        * WebProcess/WebPage/DrawingAreaImpl.cpp:
        (WebKit::DrawingAreaImpl::forceRepaint):
        If there is a layer tree host, ask it to force a repaint instead.

        * WebProcess/WebPage/LayerTreeHost.h:
        * WebProcess/WebPage/mac/LayerTreeHostMac.h:
        * WebProcess/WebPage/mac/LayerTreeHostMac.mm:
        (WebKit::LayerTreeHostMac::forceRepaint):
        Flush any layer changes, then flush and synchronize the current CA transaction.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@78729 268f45cc-cd09-0410-ab3c-d52691b4dbfc