cc : Store surface layer ids on LayerTreeHost and push them at commit

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 8db96130c74303927c5712016310f894d3d87349..da8b654de78c11251e3db336bf83ca6a36608ede 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -1092,6 +1092,26 @@ bool LayerTreeHost::PaintContent(const LayerList& update_layer_list,
   return did_paint_content;
 }
 
+void LayerTreeHost::AddSurfaceLayerId(const SurfaceId& surface_id) {
+  DCHECK(std::find(surface_layer_ids_.begin(), surface_layer_ids_.end(),
+                   surface_id) == surface_layer_ids_.end());
+  surface_layer_ids_.push_back(surface_id);
+  needs_surface_ids_sync_ = true;
+}
+
+void LayerTreeHost::RemoveSurfaceLayerId(const SurfaceId& surface_id) {
+  auto pos = std::find(surface_layer_ids_.begin(), surface_layer_ids_.end(),
+                       surface_id);
+  if (pos != surface_layer_ids_.end()) {
+    surface_layer_ids_.erase(pos);
+    needs_surface_ids_sync_ = true;
+  }
+}
+
+const std::vector<SurfaceId>& LayerTreeHost::SurfaceLayerIds() const {
+  return surface_layer_ids_;
+}
+
 void LayerTreeHost::AddLayerShouldPushProperties(Layer* layer) {
   layers_that_should_push_properties_.insert(layer);
 }