Only boxes should have child transform layers.

Source/core/rendering/compositing/CompositedLayerMapping.cpp

Index: Source/core/rendering/compositing/CompositedLayerMapping.cpp
diff --git a/Source/core/rendering/compositing/CompositedLayerMapping.cpp b/Source/core/rendering/compositing/CompositedLayerMapping.cpp
index 2cc35ccfd68be6e22dc764f3a602e78f997213b2..b5a7e42bbb5327445170866bbc0b3db043fb426e 100644
--- a/Source/core/rendering/compositing/CompositedLayerMapping.cpp
+++ b/Source/core/rendering/compositing/CompositedLayerMapping.cpp
@@ -476,7 +476,7 @@ bool CompositedLayerMapping::updateGraphicsLayerConfiguration(GraphicsLayerUpdat
     bool hasPerspective = false;
     if (RenderStyle* style = renderer->style())
         hasPerspective = style->hasPerspective();
-    bool needsChildTransformLayer = hasPerspective && (layerForChildrenTransform() == m_childTransformLayer.get());
+    bool needsChildTransformLayer = hasPerspective && (layerForChildrenTransform() == m_childTransformLayer.get()) && renderer->isBox();

[Julien - ping for review, 2014/04/17 00:02:38]

Wouldn't it make more sense not to have a RenderLayer in the non-box case as we
won't apply the perspective anyway?

[Ian Vollick, 2014/04/17 01:31:03]

I don't think that's possible here. You couldn't be composited without a
RenderLayer, but we do need a composited layer to pass on opacity info to the
composited descedants.

     if (updateChildTransformLayer(needsChildTransformLayer))
         layerConfigChanged = true;