Generalize scroll parent work in CalculateDrawProperties

cc/trees/layer_tree_host.cc

Index: cc/trees/layer_tree_host.cc
diff --git a/cc/trees/layer_tree_host.cc b/cc/trees/layer_tree_host.cc
index 08fb8105cbec1f97a71438d1aab2cba1eed28f74..6a500be12e67e486c947dfd209586cabbd690cfc 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -127,7 +127,8 @@ LayerTreeHost::LayerTreeHost(LayerTreeHostClient* client,
       id_(s_layer_tree_host_sequence_number.GetNext() + 1),
       next_commit_forces_redraw_(false),
       shared_bitmap_manager_(shared_bitmap_manager),
-      gpu_memory_buffer_manager_(gpu_memory_buffer_manager) {
+      gpu_memory_buffer_manager_(gpu_memory_buffer_manager),
+      render_surface_layer_list_id_(0) {
   if (settings_.accelerated_animation_enabled)
     animation_registrar_ = AnimationRegistrar::Create();
   rendering_stats_instrumentation_->set_record_rendering_stats(
@@ -832,10 +833,7 @@ bool LayerTreeHost::UpdateLayers(Layer* root_layer,
 
     TRACE_EVENT0("cc", "LayerTreeHost::UpdateLayers::CalcDrawProps");
     bool can_render_to_separate_surface = true;
-    // TODO(vmpstr): Passing 0 as the current render surface layer list id means
-    // that we won't be able to detect if a layer is part of |update_list|.
-    // Change this if this information is required.
-    int render_surface_layer_list_id = 0;
+    ++render_surface_layer_list_id_;
     LayerTreeHostCommon::CalcDrawPropsMainInputs inputs(
         root_layer,
         device_viewport_size(),
@@ -848,7 +846,7 @@ bool LayerTreeHost::UpdateLayers(Layer* root_layer,
         can_render_to_separate_surface,
         settings_.layer_transforms_should_scale_layer_contents,
         &update_list,
-        render_surface_layer_list_id);
+        render_surface_layer_list_id_);
     LayerTreeHostCommon::CalculateDrawProperties(&inputs);
 
     if (total_frames_used_for_lcd_text_metrics_ <=