cc: Split out calcDrawEtc from drawLayers

cc/layer_tree_host_impl.h

Index: cc/layer_tree_host_impl.h
diff --git a/cc/layer_tree_host_impl.h b/cc/layer_tree_host_impl.h
index 07afc90ed57788a863e3517c51c4e9897f38273f..74bdf725751a30e93d6448aea40b30efe265c763 100644
--- a/cc/layer_tree_host_impl.h
+++ b/cc/layer_tree_host_impl.h
@@ -248,6 +248,9 @@ public:
     void setHasTransparentBackground(bool transparent) { m_hasTransparentBackground = transparent; }
     bool needsAnimateLayers() const { return !m_activeAnimationControllers.empty(); }
 
+    bool needsUpdateDrawProperties() const { return m_needsUpdateDrawProperties; }
+    void setNeedsUpdateDrawProperties() { m_needsUpdateDrawProperties = true; }
+
     void setNeedsRedraw();
 
     void renderingStats(RenderingStats*) const;
@@ -298,8 +301,11 @@ protected:
     void animatePageScale(base::TimeTicks monotonicTime);
     void animateScrollbars(base::TimeTicks monotonicTime);
 
+    void updateDrawProperties();
+
     // Exposed for testing.
     void calculateRenderSurfaceLayerList(LayerList&);
+    void resetNeedsUpdateDrawPropertiesForTesting() { m_needsUpdateDrawProperties = false; }
 
     // Virtual for testing.
     virtual void animateLayers(base::TimeTicks monotonicTime, base::Time wallClockTime);
@@ -364,6 +370,7 @@ private:
     bool m_hasTransparentBackground;
 
     // If this is true, it is necessary to traverse the layer tree ticking the animators.
+    bool m_needsUpdateDrawProperties;
     bool m_pinchGestureActive;
     gfx::Point m_previousPinchAnchor;