Move second internal recursion to a precomputation in layer_tree_host_common.cc

cc/draw_properties.h

Index: cc/draw_properties.h
diff --git a/cc/draw_properties.h b/cc/draw_properties.h
index fc0507c6edd936262ed8b87c7c42ef8bc8353d10..e1c816525e11b803b1d337e8e87b8ac32b8ff61b 100644
--- a/cc/draw_properties.h
+++ b/cc/draw_properties.h
@@ -22,6 +22,7 @@ struct CC_EXPORT DrawProperties {
         , screen_space_transform_is_animating(false)
         , is_clipped(false)
         , render_target(0)
+        , num_descendants_that_draw_content(0)
     {
     }
 
@@ -67,6 +68,9 @@ struct CC_EXPORT DrawProperties {
     // layer. This value is used to avoid unnecessarily changing GL scissor
     // state.
     gfx::Rect clip_rect;
+
+    // Does not include this layer itself, only its children and descendants.
+    int num_descendants_that_draw_content;
 };
 
 }  // namespace cc