Ensure that layout milestones complete in all cases
https://bugs.webkit.org/show_bug.cgi?id=130101
        
Reviewed by Darin Adler.
        
Milestones fail to complete in some testing scenarios.

* dom/Document.cpp:
(WebCore::Document::setParsing):
        
    Check if we need to fire layout milestones if parsing finishes without pending layout.
    Parsing status affects whether the document is considered non-empty and that affects
    layout milestones.

    Remove explicit layout scheduling here, layout timer will be active already if there
    is a layout pending

* page/FrameView.cpp:
(WebCore::FrameView::performPostLayoutTasks):
(WebCore::FrameView::firePaintRelatedMilestonesIfNeeded):
        
    Renamed for consistency

(WebCore::FrameView::fireLayoutRelatedMilestonesIfNeeded):
        
    Factor layout milestone firing into a function.

* page/FrameView.h:



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@165534 268f45cc-cd09-0410-ab3c-d52691b4dbfc