Restore sanity to RenderLayerStackingNode::shouldBeNormalFlowOnly

Source/core/rendering/RenderLayerStackingNode.cpp

Index: Source/core/rendering/RenderLayerStackingNode.cpp
diff --git a/Source/core/rendering/RenderLayerStackingNode.cpp b/Source/core/rendering/RenderLayerStackingNode.cpp
index a750ce8b08d10930d070635fcb7fe0bce1bb8bb3..a6ad456c69f5c955a97a3415e2faf3f584441177 100644
--- a/Source/core/rendering/RenderLayerStackingNode.cpp
+++ b/Source/core/rendering/RenderLayerStackingNode.cpp
@@ -308,25 +308,7 @@ void RenderLayerStackingNode::updateStackingNodesAfterStyleChange(const RenderSt
 
 bool RenderLayerStackingNode::shouldBeNormalFlowOnly() const

[Julien - ping for review, 2014/06/06 17:31:25]

Let's put a FIXME to rename it to something else (or better just let's do it as
part of this patch) as 'normal flow' has a meaning in CSS 2.1 that we don't
match.

 {
-    RenderLayerModelObject* renderer = this->renderer();
-
-    const bool couldBeNormalFlow = renderer->hasOverflowClip()
-        || renderer->hasReflection()
-        || renderer->hasMask()
-        || renderer->isCanvas()
-        || renderer->isVideo()
-        || renderer->isEmbeddedObject()
-        || renderer->isRenderIFrame()
-        || (renderer->style()->specifiesColumns() && !layer()->isRootLayer());
-
-    const bool preventsElementFromBeingNormalFlow = renderer->isPositioned()
-        || renderer->hasTransform()
-        || renderer->hasClipPath()
-        || renderer->hasFilter()
-        || renderer->hasBlendMode()
-        || layer()->isTransparent();
-
-    return couldBeNormalFlow && !preventsElementFromBeingNormalFlow;
+    return !isStackingContext() && !renderer()->isPositioned();
 }
 
 void RenderLayerStackingNode::updateIsNormalFlowOnly()