Add infrastructure for partial layouts

Source/core/dom/Element.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc. All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 550 matching lines @@
 static int adjustForLocalZoom(LayoutUnit value, RenderObject* renderer)
 {
     float zoomFactor = localZoomForRenderer(renderer);
     if (zoomFactor == 1)
         return value;
     return lroundf(value / zoomFactor);
 }
 
 int Element::offsetLeft()
 {
-    document()->updateLayoutIgnorePendingStylesheets();
+    document()->tryPartialUpdateLayoutIgnorePendingStylesheets(renderer());
     if (RenderBoxModelObject* renderer = renderBoxModelObject())
         return adjustForLocalZoom(renderer->pixelSnappedOffsetLeft(), renderer);
     return 0;
 }
 
 int Element::offsetTop()
 {
-    document()->updateLayoutIgnorePendingStylesheets();
+    document()->tryPartialUpdateLayoutIgnorePendingStylesheets(renderer());
     if (RenderBoxModelObject* renderer = renderBoxModelObject())
         return adjustForLocalZoom(renderer->pixelSnappedOffsetTop(), renderer);
     return 0;
 }
 
 int Element::offsetWidth()
 {
     document()->updateStyleForNodeIfNeeded(this);
 
     if (RenderBox* renderer = renderBox()) {
         if (!renderer->requiresLayoutToDetermineWidth())
             return adjustLayoutUnitForAbsoluteZoom(renderer->fixedOffsetWidth(), renderer).round();
     }
 
-    document()->updateLayoutIgnorePendingStylesheets();
+    document()->tryPartialUpdateLayoutIgnorePendingStylesheets(renderer());
     if (RenderBoxModelObject* renderer = renderBoxModelObject())
         return adjustLayoutUnitForAbsoluteZoom(renderer->pixelSnappedOffsetWidth(), renderer).round();
     return 0;
 }
 
 int Element::offsetHeight()
 {
-    document()->updateLayoutIgnorePendingStylesheets();
+    document()->tryPartialUpdateLayoutIgnorePendingStylesheets(renderer());
     if (RenderBoxModelObject* renderer = renderBoxModelObject())
         return adjustLayoutUnitForAbsoluteZoom(renderer->pixelSnappedOffsetHeight(), renderer).round();
     return 0;
 }
 
 Element* Element::bindingsOffsetParent()
 {
     Element* element = offsetParent();
     if (!element || !element->isInShadowTree())
         return element;
@@ skipping 3074 matching lines @@
     return 0;
 }
 
 Attribute* UniqueElementData::attributeItem(unsigned index)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(index < length());
     return &m_attributeVector.at(index);
 }
 
 } // namespace WebCore