Reviewed by Tony Gentilcore.

        Media Stream API: add the skeleton of the frame and page controllers and the embedder client.
        https://bugs.webkit.org/show_bug.cgi?id=56922

        Add the basic outlines of the page controller, the per-frame controller and the embedder
        client interface for the Media Stream API. Provide methods to handle the situations
        where a frame is detached from the page or transferred between pages.

        Tests for the Media Stream API will be provided by the bug 56587.

        * CMakeLists.txt:
        * GNUmakefile.list.am:
        * WebCore.gypi:
        * WebCore.pro:
        * WebCore.vcproj/WebCore.vcproj:
        * WebCore.xcodeproj/project.pbxproj:
        * page/Frame.cpp:
        (WebCore::Frame::Frame):
        (WebCore::Frame::~Frame):
        (WebCore::Frame::pageDestroyed):
        (WebCore::Frame::transferChildFrameToNewDocument):
        * page/Frame.h:
        (WebCore::Frame::mediaStreamFrameController):
        * page/MediaStreamClient.h: Added.
        (WebCore::MediaStreamClient::~MediaStreamClient):
        * page/MediaStreamController.cpp: Added.
        (WebCore::MediaStreamController::Request::Request):
        (WebCore::MediaStreamController::Request::localId):
        (WebCore::MediaStreamController::Request::frameController):
        (WebCore::MediaStreamController::MediaStreamController):
        (WebCore::MediaStreamController::~MediaStreamController):
        (WebCore::MediaStreamController::unregisterFrameController):
        (WebCore::MediaStreamController::registerRequest):
        * page/MediaStreamController.h: Added.
        * page/MediaStreamFrameController.cpp: Added.
        (WebCore::MediaStreamFrameController::Request::Request):
        (WebCore::MediaStreamFrameController::Request::~Request):
        (WebCore::MediaStreamFrameController::Request::scriptExecutionContext):
        (WebCore::MediaStreamFrameController::Request::isGenerateStreamRequest):
        (WebCore::MediaStreamFrameController::Request::isRecordedDataRequest):
        (WebCore::MediaStreamFrameController::RequestMap::abort):
        (WebCore::MediaStreamFrameController::RequestMap::abortAll):
        (WebCore::MediaStreamFrameController::MediaStreamFrameController):
        (WebCore::MediaStreamFrameController::~MediaStreamFrameController):
        (WebCore::MediaStreamFrameController::securityOrigin):
        (WebCore::MediaStreamFrameController::scriptExecutionContext):
        (WebCore::MediaStreamFrameController::pageController):
        (WebCore::MediaStreamFrameController::enterDetachedState):
        (WebCore::MediaStreamFrameController::disconnectPage):
        (WebCore::MediaStreamFrameController::disconnectFrame):
        (WebCore::MediaStreamFrameController::transferToNewPage):
        * page/MediaStreamFrameController.h: Added.
        * page/Page.cpp:
        (WebCore::Page::Page):
        (WebCore::Page::PageClients::PageClients):
        * page/Page.h:
        (WebCore::Page::mediaStreamController):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@85745 268f45cc-cd09-0410-ab3c-d52691b4dbfc