Introduces a new RunLoopTimer class that has an API mimicking Timer but
        allows it to be scheduled with one or more SchedulePairs.

        <rdar://problem/6687342> -[WebView scheduleInRunLoop:forMode:] has no affect on timers

        Reviewed by Darin Adler.

        * WebCore.xcodeproj/project.pbxproj: Adds the new RunLoopTimer.{cpp,h} files.
        * loader/MainResourceLoader.cpp:
        (WebCore::MainResourceLoader::handleDataLoadNow): Use the MainResourceLoaderTimer typedef.
        (WebCore::MainResourceLoader::startDataLoadTimer): Added. Start the timer and on
        Mac platforms also schedule with the Page's SchedulePairs.
        (WebCore::MainResourceLoader::handleDataLoadSoon): Call startDataLoadTimer().
        (WebCore::MainResourceLoader::setDefersLoading): Ditto.
        * loader/MainResourceLoader.h:
        * platform/cf/RunLoopTimerCF.cpp: Added.
        (WebCore::RunLoopTimerBase::~RunLoopTimerBase):
        (WebCore::timerFired):
        (WebCore::RunLoopTimerBase::start):
        (WebCore::RunLoopTimerBase::schedule):
        (WebCore::RunLoopTimerBase::stop):
        (WebCore::RunLoopTimerBase::isActive):
        * platform/RunLoopTimer.h: Added.
        (WebCore::RunLoopTimerBase::RunLoopTimerBase):
        (WebCore::RunLoopTimerBase::startRepeating):
        (WebCore::RunLoopTimerBase::startOneShot):
        (WebCore::RunLoopTimer::RunLoopTimer):
        (WebCore::RunLoopTimer::fired):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@41845 268f45cc-cd09-0410-ab3c-d52691b4dbfc