Reviewed by Darin Adler.

        https://bugs.webkit.org/show_bug.cgi?id=22755
        Prepare to add create/remove timeout methods to JSWorkerContext by moving
        timer-specific code from JSDOMWindowBase to DOMTimer.
        Moved everything JS-related from DOMTimer to ScheduledAction.
        Now ScheduledAction is what it wanted to be all the time: a JS engine-specific 
        container for timer callback that knows how to invoke it.
        DOMTimer is not anymore JS-specific.

        This is mostly moving the code around. No intended functional changes.

        * bindings/js/DOMTimer.cpp:
        (WebCore::DOMTimer::DOMTimer):
        (WebCore::DOMTimer::~DOMTimer):
        (WebCore::DOMTimer::install):
        (WebCore::DOMTimer::removeById):
        (WebCore::DOMTimer::fired):
        (WebCore::DOMTimer::stop):
        * bindings/js/DOMTimer.h:
        * bindings/js/JSDOMWindowBase.cpp:
        (WebCore::JSDOMWindowBase::installTimeout):
        (WebCore::JSDOMWindowBase::removeTimeout):
        * bindings/js/JSDOMWindowBase.h:
        * bindings/js/ScheduledAction.cpp:
        (WebCore::ScheduledAction::execute):
        * bindings/js/ScheduledAction.h:
        * dom/Document.cpp:
        (WebCore::Document::addTimeout):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@39489 268f45cc-cd09-0410-ab3c-d52691b4dbfc