Move second internal recursion to a precomputation in layer_tree_host_common.cc

cc/delegated_renderer_layer_impl.cc

Index: cc/delegated_renderer_layer_impl.cc
diff --git a/cc/delegated_renderer_layer_impl.cc b/cc/delegated_renderer_layer_impl.cc
index 7907454f97fbe43dd2ffd78cc3d81d6521c35231..d59bc0029bab51f816b1a7f12196ec3a6164d329 100644
--- a/cc/delegated_renderer_layer_impl.cc
+++ b/cc/delegated_renderer_layer_impl.cc
@@ -22,13 +22,13 @@ DelegatedRendererLayerImpl::~DelegatedRendererLayerImpl()
     clearRenderPasses();
 }
 
-int DelegatedRendererLayerImpl::descendantsDrawContent()
+int DelegatedRendererLayerImpl::numDescendantsThatDrawContent()
 {
-    // FIXME: This could possibly return false even though there are some
-    // quads present as they could all be from a single layer (or set of
-    // layers without children). If this happens, then make a test that
-    // ensures the opacity is being changed on quads in the root RenderPass
-    // when this layer doesn't own a RenderSurfaceImpl.
+    // FIXME: This could eventually return an exact layer count even though
+    // there are some quads present as they could all be from a single layer
+    // (or set of layers without children). If this happens, then make a test
+    // that ensures the opacity is being changed on quads in the root
+    // RenderPass when this layer doesn't own a RenderSurfaceImpl.
     return m_renderPassesInDrawOrder.isEmpty() ? 0 : 2;
 }