Fix RenderLayer::collectLayers logic bug.

Source/core/rendering/RenderLayer.h

Index: Source/core/rendering/RenderLayer.h
diff --git a/Source/core/rendering/RenderLayer.h b/Source/core/rendering/RenderLayer.h
index b7b6286e0ce44f3c41a470eb75e1abadef25f327..94ae8754fb5aa00a26cf8e07a67542bcb8cddf18 100644
--- a/Source/core/rendering/RenderLayer.h
+++ b/Source/core/rendering/RenderLayer.h
@@ -44,6 +44,7 @@
 #ifndef RenderLayer_h
 #define RenderLayer_h
 
+#include "core/page/Settings.h"
 #include "core/platform/ScrollableArea.h"
 #include "core/rendering/PaintInfo.h"
 #include "core/rendering/RenderBox.h"
@@ -824,12 +825,10 @@ public:
     void computePaintOrderList(PaintOrderListType type, Vector<RefPtr<Node> >&);
 
 private:
-    enum CollectLayersBehavior { StopAtStackingContexts, StopAtStackingContainers };
-
     void updateZOrderLists();
     void rebuildZOrderLists();
     // See the comment for collectLayers for information about the layerToForceAsStackingContainer parameter.
-    void rebuildZOrderLists(CollectLayersBehavior, OwnPtr<Vector<RenderLayer*> >&, OwnPtr<Vector<RenderLayer*> >&, const RenderLayer* layerToForceAsStackingContainer = 0);
+    void rebuildZOrderLists(OwnPtr<Vector<RenderLayer*> >&, OwnPtr<Vector<RenderLayer*> >&, const RenderLayer* layerToForceAsStackingContainer = 0, AcceleratedCompositingForOverflowScrollEnabledMode = AcceleratedCompositingForOverflowScrollEnabled);

[shawnsingh, 2013/05/16 09:47:54]

Actually my problem wasn't really with the naming, but the fact that this looks
like an assignment, rather than obviously being a default parameter.  It guess
it's not too big a deal, though.

     void clearZOrderLists();
 
     void updateNormalFlowList();
@@ -908,7 +907,7 @@ private:
     // post-promotion layer lists, by allowing us to treat a layer as if it is a
     // stacking context, without adding a new member to RenderLayer or modifying
     // the style (which could cause extra allocations).
-    void collectLayers(bool includeHiddenLayers, CollectLayersBehavior, OwnPtr<Vector<RenderLayer*> >&, OwnPtr<Vector<RenderLayer*> >&, const RenderLayer* layerToForceAsStackingContainer = 0);
+    void collectLayers(bool includeHiddenLayers, OwnPtr<Vector<RenderLayer*> >&, OwnPtr<Vector<RenderLayer*> >&, const RenderLayer* layerToForceAsStackingContainer = 0, AcceleratedCompositingForOverflowScrollEnabledMode = AcceleratedCompositingForOverflowScrollEnabled);
 
     struct LayerPaintingInfo {
         LayerPaintingInfo(RenderLayer* inRootLayer, const LayoutRect& inDirtyRect, PaintBehavior inPaintBehavior, const LayoutSize& inSubPixelAccumulation, RenderObject* inPaintingRoot = 0, RenderRegion*inRegion = 0, OverlapTestRequestMap* inOverlapTestRequests = 0)
@@ -991,7 +990,7 @@ private:
     bool hasScrollableHorizontalOverflow() const;
     bool hasScrollableVerticalOverflow() const;
 
-    bool shouldBeNormalFlowOnly() const;
+    bool shouldBeNormalFlowOnly(AcceleratedCompositingForOverflowScrollEnabledMode = AcceleratedCompositingForOverflowScrollEnabled) const;
 
     bool shouldBeSelfPaintingLayer() const;