https://bugs.webkit.org/show_bug.cgi?id=81419
        <rdar://problem/11066794>

        Reviewed by Darin Adler.

        Mostly a copy/paste of DRT code.

        Tested manually by making sure that editing/pasteboard/copy-image-with-alt-text.html
        doesn't interfere with my clipboard while being run in a loop.

        * WebKitTestRunner/WebKitTestRunner.xcodeproj/project.pbxproj:
        * WebKitTestRunner/mac/PoseAsClass.h: Added.
        * WebKitTestRunner/mac/PoseAsClass.mm: Added.
        * WebKitTestRunner/mac/TestControllerMac.mm:
        (WTR::TestController::platformInitialize):
        (WTR::TestController::platformDestroy):
        * WebKitTestRunner/mac/WebKitTestRunnerPasteboard.h: Added.
        * WebKitTestRunner/mac/WebKitTestRunnerPasteboard.mm: Added.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@154640 268f45cc-cd09-0410-ab3c-d52691b4dbfc