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 c39cd6da54ab73f0c139420874daed59f33898ed..95cfcf5bf6915e1fa6e4c49cbece5f9e5b7e4363 100644
--- a/cc/layer_impl.h
+++ b/cc/layer_impl.h
@@ -78,7 +78,7 @@ public:
     bool replicaHasMask() const { return m_replicaLayer && (m_maskLayer || m_replicaLayer->m_maskLayer); }
 
     LayerTreeHostImpl* layerTreeHostImpl() const { return m_layerTreeHostImpl; }
-    void setLayerTreeHostImpl(LayerTreeHostImpl* hostImpl) { m_layerTreeHostImpl = hostImpl; }
+    void setLayerTreeHostImpl(LayerTreeHostImpl* hostImpl);
 
     scoped_ptr<SharedQuadState> createSharedQuadState() const;
     // willDraw must be called before appendQuads. If willDraw is called,
@@ -161,6 +161,8 @@ public:
 
     bool showDebugBorders() const;
 
+    // Creating and destroying render surfaces should only be performed by

[danakj, 2012/12/06 19:12:10]

I'm not sure about the destroying part here? Won't they be destroyed during tree
sync if the layer is destroyed, etc?

[enne (OOO), 2012/12/06 19:25:42]

So, here's my thought process.  Setting a draw property should not
setNeedsUpdateDrawProperties(); only setting non-derived properties should cause
that.

More importantly, destroying/creating a render surface invalidates the RSLL
which is now held between frames, and really only the host can manage that. 
I'll update this comment to be more accurate that the caller is responsible for
calling setNeedsUpdateDrawProperties.

+    // calcDrawProperties.
     void createRenderSurface();
     void clearRenderSurface() { m_drawProperties.render_surface.reset(); }
 
@@ -295,6 +297,8 @@ 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.