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 21c44f0a9a74c2f85a24b648f7c94e4de2607ef9..ee9f73e8c0d8580bf279723b471ffe1c1ba5a036 100644
--- a/third_party/WebKit/Source/platform/graphics/GraphicsLayer.h
+++ b/third_party/WebKit/Source/platform/graphics/GraphicsLayer.h
@@ -271,6 +271,7 @@ 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.
@@ -278,6 +279,7 @@ protected:
     // for testing
     friend class CompositedLayerMappingTest;
     friend class FakeGraphicsLayerFactory;
+    friend class CompositedLayerMappingTest;
 
 private:
     // Adds a child without calling updateChildList(), so that adding children