Separate repaint and layout requirements of StyleDifference (Step 1)

Source/core/rendering/RenderBox.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. 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 135 matching lines @@
     if (isOutOfFlowPositioned())
         RenderBlock::removePositionedObject(this);
 }
 
 void RenderBox::styleWillChange(StyleDifference diff, const RenderStyle& newStyle)
 {
     RenderStyle* oldStyle = style();
     if (oldStyle) {
         // The background of the root element or the body element could propagate up to
         // the canvas.  Just dirty the entire canvas when our style changes substantially.
-        if (diff >= StyleDifferenceRepaint && node() &&
-            (isHTMLHtmlElement(*node()) || isHTMLBodyElement(*node()))) {
+        if (diff.needsRepaint() && node()
+            && (isHTMLHtmlElement(*node()) || isHTMLBodyElement(*node()))) {
 
-            if (!RuntimeEnabledFeatures::repaintAfterLayoutEnabled() || diff != StyleDifferenceLayout)
+            if (!RuntimeEnabledFeatures::repaintAfterLayoutEnabled() || !diff.needsFullLayout())
                 view()->repaint();
 
             if (oldStyle->hasEntirelyFixedBackground() != newStyle.hasEntirelyFixedBackground())
                 view()->compositor()->setNeedsUpdateFixedBackground();
         }
 
         // When a layout hint happens and an object's position style changes, we have to do a layout
         // to dirty the render tree using the old position value now.
-        if (diff == StyleDifferenceLayout && parent() && oldStyle->position() != newStyle.position()) {
+        if (diff.needsFullLayout() && parent() && oldStyle->position() != newStyle.position()) {
             markContainingBlocksForLayout();
             if (oldStyle->position() == StaticPosition)
                 repaint();
             else if (newStyle.hasOutOfFlowPosition())
                 parent()->setChildNeedsLayout();
             if (isFloating() && !isOutOfFlowPositioned() && newStyle.hasOutOfFlowPosition())
                 removeFloatingOrPositionedChildFromBlockLists();
         }
     // FIXME: This branch runs when !oldStyle, which means that layout was never called
     // so what's the point in invalidating the whole view that we never painted?
@@ skipping 35 matching lines @@
             left = (left / oldStyle->effectiveZoom()) * newStyle->effectiveZoom();
             layer()->scrollableArea()->scrollToXOffset(left);
         }
         if (int top = layer()->scrollableArea()->scrollYOffset()) {
             top = (top / oldStyle->effectiveZoom()) * newStyle->effectiveZoom();
             layer()->scrollableArea()->scrollToYOffset(top);
         }
     }
 
     // Our opaqueness might have changed without triggering layout.
-    if (diff == StyleDifferenceRepaint || diff == StyleDifferenceRepaintLayer) {
+    if (diff.needsRepaint()) {
         RenderObject* parentToInvalidate = parent();
         for (unsigned i = 0; i < backgroundObscurationTestMaxDepth && parentToInvalidate; ++i) {
             parentToInvalidate->invalidateBackgroundObscurationStatus();
             parentToInvalidate = parentToInvalidate->parent();
         }
     }
 
     if (isDocumentElement() || isBody())
         document().view()->recalculateScrollbarOverlayStyle();
 
@@ skipping 4513 matching lines @@
         return 0;
 
     if (!layoutState && !flowThreadContainingBlock())
         return 0;
 
     RenderBlock* containerBlock = containingBlock();
     return containerBlock->offsetFromLogicalTopOfFirstPage() + logicalTop();
 }
 
 } // namespace WebCore