Merge 106459 - Fix the semantics of passing contentsVisible flag to GraphicsLayers

Source/WebCore/rendering/RenderLayerBacking.cpp

Index: Source/WebCore/rendering/RenderLayerBacking.cpp
===================================================================
--- Source/WebCore/rendering/RenderLayerBacking.cpp	(revision 106839)
+++ Source/WebCore/rendering/RenderLayerBacking.cpp	(working copy)
@@ -403,8 +403,12 @@
 #endif
     
     m_owningLayer->updateVisibilityStatus();
-    m_graphicsLayer->setContentsVisible(m_owningLayer->hasVisibleContent());
-    
+
+    // m_graphicsLayer is the corresponding GraphicsLayer for this RenderLayer and its non-compositing
+    // descendants. So, the visibility flag for m_graphicsLayer should be true if there are any
+    // non-compositing visible layers.
+    m_graphicsLayer->setContentsVisible(m_owningLayer->hasVisibleContent() || hasVisibleNonCompositingDescendantLayers());
+
     RenderStyle* style = renderer()->style();
     m_graphicsLayer->setPreserves3D(style->transformStyle3D() == TransformStyle3DPreserve3D && !renderer()->hasReflection());
     m_graphicsLayer->setBackfaceVisibility(style->backfaceVisibility() == BackfaceVisibilityVisible);