Move second internal recursion to a precomputation in layer_tree_host_common.cc

cc/layer.h

Index: cc/layer.h
diff --git a/cc/layer.h b/cc/layer.h
index 641800bc81270a9a3a7900ca7f3b72a4b8f2c285..9571a2dacbaebbb099eb6852e71ef16718dc74bf 100644
--- a/cc/layer.h
+++ b/cc/layer.h
@@ -198,6 +198,7 @@ public:
 
     virtual void setLayerTreeHost(LayerTreeHost*);
 
+    bool hasDelegatedContent() const { return false; }
     bool hasContributingDelegatedRenderPasses() const { return false; }
 
     void setIsDrawable(bool);
@@ -249,11 +250,6 @@ public:
     void setBoundsContainPageScale(bool);
     bool boundsContainPageScale() const { return m_boundsContainPageScale; }
 
-    // Returns 0 if none of the layer's descendants has content to draw,
-    // 1 if exactly one descendant has content to draw, or a number >1
-    // (but necessary the exact number of descendants) otherwise.
-    int descendantsDrawContent();
-
     LayerTreeHost* layerTreeHost() const { return m_layerTreeHost; }
 
     // Set the priority of all desired textures in this layer.