cc: Split out calcDrawEtc from drawLayers

cc/layer_impl.h

Index: cc/layer_impl.h
diff --git a/cc/layer_impl.h b/cc/layer_impl.h
index e155e49fdf6bcd28c88d3120505e5d17d5eeb7ee..3d9a6f5fd0c3426af7b6f68f1fcae3e8c4070f9d 100644
--- a/cc/layer_impl.h
+++ b/cc/layer_impl.h
@@ -155,6 +155,9 @@ public:
 
     bool showDebugBorders() const;
 
+    // These invalidate the host's render surface layer list.  The caller
+    // is responsible for calling setNeedsUpdateDrawProperties on the host
+    // so that its list can be recreated.
     void createRenderSurface();
     void clearRenderSurface() { m_drawProperties.render_surface.reset(); }
 
@@ -290,6 +293,8 @@ private:
     friend class TreeSynchronizer;
     void clearChildList(); // Warning: This does not preserve tree structure invariants and so is only exposed to the tree synchronizer.
 
+    void noteLayerSurfacePropertyChanged();
+    void noteLayerPropertyChanged();
     void noteLayerPropertyChangedForSubtree();
 
     // Note carefully this does not affect the current layer.