Add StyleChangeState to get rid of a bunch of static state in the render tree.

Source/WebCore/rendering/RenderObject.h

Index: Source/WebCore/rendering/RenderObject.h
diff --git a/Source/WebCore/rendering/RenderObject.h b/Source/WebCore/rendering/RenderObject.h
index b5a7da4b667b5d9996a882dfb94f864869f65353..f30d9f08114b379929c4efaadf4bc7b77a6ce4df 100644
--- a/Source/WebCore/rendering/RenderObject.h
+++ b/Source/WebCore/rendering/RenderObject.h
@@ -148,6 +148,34 @@ typedef WTF::HashSet<const RenderObject*> RenderObjectAncestorLineboxDirtySet;
 const int showTreeCharacterOffset = 39;
 #endif
 
+struct StyleChangeState {
+    // RenderObject
+    unsigned affectsParentBlock : 1;
+
+    // RenderLayerModelObject
+    unsigned wasFloating : 1;
+    unsigned hadLayer : 1;
+    unsigned hadTransform : 1;
+    unsigned layerWasSelfPainting : 1;
+
+    // RenderBox
+    unsigned hadOverflowClip : 1;
+
+    // RenderBlock
+    unsigned couldPropagateFloatIntoSibling : 1;
+
+    StyleChangeState() :
+        affectsParentBlock(0),

[eseidel, 2013/04/05 01:50:36]

I take it the compiler doesn't like "false"?

[esprehn, 2013/04/17 03:29:01]

Nah, I was just moving fast. I'll change to false.

+        wasFloating(0),
+        hadLayer(0),
+        hadTransform(0),
+        layerWasSelfPainting(0),
+        hadOverflowClip(0),
+        couldPropagateFloatIntoSibling(0)
+    {
+    }
+};
+
 // Base class for all rendering tree objects.
 class RenderObject : public CachedImageClient {
     friend class RenderBlock;
@@ -999,9 +1027,9 @@ protected:
     inline bool layerCreationAllowedForSubtree() const;
 
     // Overrides should call the superclass at the end
-    virtual void styleWillChange(StyleDifference, const RenderStyle* newStyle);
+    virtual void styleWillChange(StyleDifference, const RenderStyle* newStyle, StyleChangeState&);
     // Overrides should call the superclass at the start
-    virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle);
+    virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle, const StyleChangeState&);
     void propagateStyleToAnonymousChildren(bool blockChildrenOnly = false);
 
     void drawLineForBoxSide(GraphicsContext*, int x1, int y1, int x2, int y2, BoxSide,
@@ -1169,10 +1197,6 @@ private:
     void setNeedsSimplifiedNormalFlowLayout(bool b) { m_bitfields.setNeedsSimplifiedNormalFlowLayout(b); }
     void setIsDragging(bool b) { m_bitfields.setIsDragging(b); }
     void setEverHadLayout(bool b) { m_bitfields.setEverHadLayout(b); }
-
-private:
-    // Store state between styleWillChange and styleDidChange
-    static bool s_affectsParentBlock;
 };
 
 inline bool RenderObject::documentBeingDestroyed() const