Suppress layer creation for descendants of GPU-rasterized layers

Source/core/rendering/RenderLayer.cpp

Index: Source/core/rendering/RenderLayer.cpp
diff --git a/Source/core/rendering/RenderLayer.cpp b/Source/core/rendering/RenderLayer.cpp
index 64569c78984db8e5fa00d1806b104a7616b113f3..c9c87a65305fb00c0be04897afd2c7b6a2c9b80c 100644
--- a/Source/core/rendering/RenderLayer.cpp
+++ b/Source/core/rendering/RenderLayer.cpp
@@ -805,10 +805,10 @@ void RenderLayer::updateScrollingStateAfterCompositingChange()
         }
     }
 
-    m_compositingProperties.hasNonCompositedChild = false;
+    compositingProperties().hasNonCompositedChild = false;
     for (RenderLayer* child = firstChild(); child; child = child->nextSibling()) {
         if (child->compositingState() == NotComposited) {
-            m_compositingProperties.hasNonCompositedChild = true;
+            compositingProperties().hasNonCompositedChild = true;
             return;
         }
     }
@@ -1203,9 +1203,9 @@ void RenderLayer::clearChildNeedsToUpdateAncestorDependantProperties()
 void RenderLayer::setCompositingReasons(CompositingReasons reasons, CompositingReasons mask)
 {
     ASSERT(reasons == (reasons & mask));
-    if ((m_compositingProperties.compositingReasons & mask) == (reasons & mask))
+    if ((compositingProperties().compositingReasons & mask) == (reasons & mask))
         return;

[abarth-chromium, 2014/04/17 17:29:51]

This mask argument might not be needed anymore now that we store the
style-determined reasons separately.

[ajuma, 2014/04/17 19:24:44]

RenderLayerCompositor::updateDirectCompositingReasons calls this with mask
CompositingReasonComboAllDirectReasons, so we still need the mask argument for
now.

-    m_compositingProperties.compositingReasons = (reasons & mask) | (m_compositingProperties.compositingReasons & ~mask);
+    compositingProperties().compositingReasons = (reasons & mask) | (compositingProperties().compositingReasons & ~mask);
     m_clipper.setCompositingClipRectsDirty();
 }