https://bugs.webkit.org/show_bug.cgi?id=113613

        Reviewed by Sam Weinig.

        FeatureObserver used to depend on chromium-only HistogramSupport, which is not
        really usable on Mac at least.

        Instead of adding parallel feature reporting machinery, I'm adding a way to
        generically relay the data from FeatureObserver to port code.

        * loader/FrameLoader.cpp:
        (WebCore::FrameLoader::loadWithDocumentLoader):
        (WebCore::FrameLoader::commitProvisionalLoad):
        (WebCore::FrameLoader::reportMemoryUsage):
        * loader/FrameLoader.h:
        (WebCore::FrameLoader::previousURL):
        Exposed m_previousURL, renaming it to follow WebKit style.

        * page/FeatureObserver.cpp:
        (WebCore::FeatureObserver::~FeatureObserver):
        (WebCore::FeatureObserver::updateMeasurements):
        * page/FeatureObserver.h:
        (WebCore::FeatureObserver::accumulatedFeatureBits):
        Exposed the data to clients, and made reporting through HistogramSupport
        chromium only for clarity.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@147260 268f45cc-cd09-0410-ab3c-d52691b4dbfc