Reviewed by Adam Roben.

        Pixel tests don't work in WebKitTestRunner on Windows
        https://bugs.webkit.org/show_bug.cgi?id=56630

        Cross-platformize (Mac and Windows CG) the pixel dumping code in WebKitTestRunner to use WebKit2
        built-in snapshotting instead of using the window server on the Mac.

        * WebKitTestRunner/InjectedBundle/InjectedBundle.cpp:
        (WTR::InjectedBundle::InjectedBundle):
        (WTR::InjectedBundle::didReceiveMessage):
        (WTR::InjectedBundle::beginTesting):
        (WTR::InjectedBundle::done):
        * WebKitTestRunner/InjectedBundle/InjectedBundle.h:
        (WTR::InjectedBundle::setPixelResult):
        (WTR::InjectedBundle::shouldDumpPixels):
        * WebKitTestRunner/InjectedBundle/InjectedBundlePage.cpp:
        (WTR::InjectedBundlePage::dump):
        Take the snapshot in the bundle and send it to the UIProcess for dumping.

        * WebKitTestRunner/TestInvocation.cpp:
        (WTR::TestInvocation::invoke):
        (WTR::TestInvocation::dump):
        (WTR::TestInvocation::didReceiveMessageFromInjectedBundle):
        * WebKitTestRunner/TestInvocation.h:
        * WebKitTestRunner/cg: Added.
        * WebKitTestRunner/cg/TestInvocationCG.cpp: Copied from WebKitTestRunner/mac/TestInvocationMac.mm.
        (WTR::createCGContextFromImage):
        (WTR::computeMD5HashStringForContext):
        (WTR::TestInvocation::dumpPixelsAndCompareWithExpected):
        * WebKitTestRunner/mac/TestInvocationMac.mm: Removed.
        Making pixel dumping code shared for CG ports. Also use the WTF/MD5 instead of platform specific code.

        * WebKitTestRunner/win/TestInvocationWin.cpp:
        (WTR::TestInvocation::dumpPixelsAndCompareWithExpected):
        Keep stub for Cairo build.

        * WebKitTestRunner/Configurations/WebKitTestRunnerCoreGraphics.vsprops: Added.
        Add CG configuration.

        * WebKitTestRunner/WebKitTestRunner.xcodeproj/project.pbxproj:
        * WebKitTestRunner/win/WebKitTestRunner.vcproj:
        Add new files.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@81494 268f45cc-cd09-0410-ab3c-d52691b4dbfc