Fix flattening for scrollable areas.

third_party/WebKit/Source/platform/graphics/GraphicsLayer.h

Index: third_party/WebKit/Source/platform/graphics/GraphicsLayer.h
diff --git a/third_party/WebKit/Source/platform/graphics/GraphicsLayer.h b/third_party/WebKit/Source/platform/graphics/GraphicsLayer.h
index 371b1f1f8084b1e8065ca80952903fe07c9acfc9..929638937bb64d6d3ffec80134ea3f68e9c40d54 100644
--- a/third_party/WebKit/Source/platform/graphics/GraphicsLayer.h
+++ b/third_party/WebKit/Source/platform/graphics/GraphicsLayer.h
@@ -269,6 +269,7 @@ public:
 
 protected:
     String debugName(cc::Layer*) const;
+    bool shouldFlattenTransform() const { return m_shouldFlattenTransform; }
 
     explicit GraphicsLayer(GraphicsLayerClient*);
     // GraphicsLayerFactoryChromium that wants to create a GraphicsLayer need to be friends.
@@ -276,6 +277,7 @@ protected:
     // for testing
     friend class CompositedLayerMappingTest;
     friend class FakeGraphicsLayerFactory;
+    friend class CompositedLayerMappingTest;
 
 private:
     // Adds a child without calling updateChildList(), so that adding children