Add infrastructure for partial layouts

Source/core/page/FrameView.h

 /*
    Copyright (C) 1997 Martin Jones (mjones@kde.org)
              (C) 1998 Waldo Bastian (bastian@kde.org)
              (C) 1998, 1999 Torben Weis (weis@kde.org)
              (C) 1999 Lars Knoll (knoll@kde.org)
              (C) 1999 Antti Koivisto (koivisto@kde.org)
    Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
@@ skipping 319 matching lines @@
     void setInProgrammaticScroll(bool programmaticScroll) { m_inProgrammaticScroll = programmaticScroll; }
 
     void setHasSoftwareFilters(bool hasSoftwareFilters) { m_hasSoftwareFilters = hasSoftwareFilters; }
     bool hasSoftwareFilters() const { return m_hasSoftwareFilters; }
 
     virtual bool isActive() const OVERRIDE;
 
     // DEPRECATED: Use viewportConstrainedVisibleContentRect() instead.
     IntSize scrollOffsetForFixedPosition() const;
 
+    bool canStopPartialLayout() const { return m_canStopPartialLayout; }
+    void checkPartialLayoutComplete(RenderObject*);
+    void setStopLayoutAtRenderer(RenderObject* renderer) { m_stopLayoutAtRenderer = renderer; }
+    void resetPartialLayoutState() { m_stopLayoutAtRenderer = 0; m_canStopPartialLayout = false; }
+
 protected:
     virtual bool scrollContentsFastPath(const IntSize& scrollDelta, const IntRect& rectToScroll, const IntRect& clipRect);
     virtual void scrollContentsSlowPath(const IntRect& updateRect);
 
     virtual bool isVerticalDocument() const;
     virtual bool isFlippedDocument() const;
 
 private:
     explicit FrameView(Frame*);
 
@@ skipping 170 matching lines @@
     OwnPtr<ViewportConstrainedObjectSet> m_viewportConstrainedObjects;
 
     static double s_normalDeferredRepaintDelay;
     static double s_initialDeferredRepaintDelayDuringLoading;
     static double s_maxDeferredRepaintDelayDuringLoading;
     static double s_deferredRepaintDelayIncrementDuringLoading;
 
     bool m_hasSoftwareFilters;
 
     float m_visibleContentScaleFactor;
+
+    bool m_canStopPartialLayout;
+    RenderObject* m_stopLayoutAtRenderer;
 };
 
 inline void FrameView::incrementVisuallyNonEmptyCharacterCount(unsigned count)
 {
     if (m_isVisuallyNonEmpty)
         return;
     m_visuallyNonEmptyCharacterCount += count;
     // Use a threshold value to prevent very small amounts of visible content from triggering didFirstVisuallyNonEmptyLayout.
     // The first few hundred characters rarely contain the interesting content of the page.
     static const unsigned visualCharacterThreshold = 200;
@@ skipping 33 matching lines @@
     ASSERT(!widget || widget->isFrameView());
     return static_cast<const FrameView*>(widget);
 }
 
 // This will catch anyone doing an unnecessary cast.
 void toFrameView(const FrameView*);
 
 } // namespace WebCore
 
 #endif // FrameView_h