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

cc/layers/surface_layer.cc

Index: cc/layers/surface_layer.cc
diff --git a/cc/layers/surface_layer.cc b/cc/layers/surface_layer.cc
index 573f97b9b13280a3c9f5806052f0c7d81e52bd74..c8548813fa215fafbdd94c43db879b2b6903ee0f 100644
--- a/cc/layers/surface_layer.cc
+++ b/cc/layers/surface_layer.cc
@@ -63,12 +63,27 @@ SurfaceLayer::~SurfaceLayer() {
   DCHECK(!layer_tree_host());
 }
 
+void SurfaceLayer::AddSurfaceId(const SurfaceInfo& surface_info) {
+  DCHECK(layer_tree_host());
+  if (surface_info.is_valid())
+    layer_tree_host()->AddSurfaceLayerId(surface_info.id());
+}
+
+void SurfaceLayer::RemoveSurfaceId(const SurfaceInfo& surface_info) {
+  DCHECK(layer_tree_host());
+  if (surface_info.is_valid())
+    layer_tree_host()->RemoveSurfaceLayerId(surface_info.id());
+}
+
 void SurfaceLayer::SetPrimarySurfaceInfo(const SurfaceInfo& surface_info) {
   RemoveReference(std::move(primary_reference_returner_));
+  if (layer_tree_host())
+    RemoveSurfaceId(primary_surface_info_);
   primary_surface_info_ = surface_info;
   if (layer_tree_host()) {
     primary_reference_returner_ = ref_factory_->CreateReference(
         layer_tree_host(), primary_surface_info_.id());
+    AddSurfaceId(primary_surface_info_);
   }
   UpdateDrawsContent(HasDrawableContent());
   SetNeedsCommit();
@@ -76,10 +91,13 @@ void SurfaceLayer::SetPrimarySurfaceInfo(const SurfaceInfo& surface_info) {
 
 void SurfaceLayer::SetFallbackSurfaceInfo(const SurfaceInfo& surface_info) {
   RemoveReference(std::move(fallback_reference_returner_));
+  if (layer_tree_host())
+    RemoveSurfaceId(fallback_surface_info_);
   fallback_surface_info_ = surface_info;
   if (layer_tree_host()) {
     fallback_reference_returner_ = ref_factory_->CreateReference(
         layer_tree_host(), fallback_surface_info_.id());
+    AddSurfaceId(fallback_surface_info_);
   }
   SetNeedsCommit();
 }
@@ -104,6 +122,11 @@ void SurfaceLayer::SetLayerTreeHost(LayerTreeHost* host) {
     Layer::SetLayerTreeHost(host);
     return;
   }
+
+  if (layer_tree_host()) {
+    RemoveSurfaceId(primary_surface_info_);
+    RemoveSurfaceId(fallback_surface_info_);

[Fady Samuel, 2017/05/24 22:31:14]

This breaks surface synchronization and surface references because
|referenced_surfaces| and |activation_dependencies| are expected to be
disjointed sets. |activation_dependencies| don't necessarily yet exist.

[jaydasika, 2017/05/24 22:43:03]

I did not understand how removing surface ids from the old LayerTreeHost breaks
that. Can you elaborate ?

+  }
   RemoveReference(std::move(primary_reference_returner_));
   RemoveReference(std::move(fallback_reference_returner_));
   Layer::SetLayerTreeHost(host);
@@ -116,6 +139,8 @@ void SurfaceLayer::SetLayerTreeHost(LayerTreeHost* host) {
       fallback_reference_returner_ = ref_factory_->CreateReference(
           layer_tree_host(), fallback_surface_info_.id());
     }
+    AddSurfaceId(primary_surface_info_);
+    AddSurfaceId(fallback_surface_info_);
   }
 }