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..e7b0c4da4e63f1d93cabc4c3f5593ee3fa5b64fd 100644
--- a/cc/layers/surface_layer.cc
+++ b/cc/layers/surface_layer.cc
@@ -63,23 +63,48 @@ SurfaceLayer::~SurfaceLayer() {
   DCHECK(!layer_tree_host());
 }
 
+static inline const SurfaceId* GetReferencedSurfaceId(
+    const SurfaceInfo& surface_info) {
+  return surface_info.is_valid() ? &surface_info.id() : nullptr;
+}
+
 void SurfaceLayer::SetPrimarySurfaceInfo(const SurfaceInfo& surface_info) {
+  const SurfaceId* old_surface_id =
+      GetReferencedSurfaceId(primary_surface_info_);
   RemoveReference(std::move(primary_reference_returner_));
   primary_surface_info_ = surface_info;
   if (layer_tree_host()) {
     primary_reference_returner_ = ref_factory_->CreateReference(
         layer_tree_host(), primary_surface_info_.id());
+    const SurfaceId* new_surface_id =
+        GetReferencedSurfaceId(primary_surface_info_);
+    if (old_surface_id != new_surface_id) {

[enne (OOO), 2017/05/24 21:57:42]

Hmm.  This check is comparing pointers? Can you have the same surface id by
value but different pointers? That said, it looks like callers of this function
already don't call it if the surface id hasn't changed, so I'm not sure it's
worth having the conditional.

I feel like all this code could be simplified too if you had a
AddSurfaceId(SurfaceInfo&) and RemoveSurfaceId(SurfaceInfo&) that had the
conditional inside of it, and then you don't need the const SurfaceId*
everywhere.  You'd just need RemoveSurfaceId(primary_surface_info_) and then
AddSurfaceId(primary_surface_info) here and elsewhere.

Does that sound reasonable?

[jaydasika, 2017/05/24 22:12:56]

Done.

+      if (old_surface_id)
+        layer_tree_host()->RemoveSurfaceLayerId(*old_surface_id);
+      if (new_surface_id)
+        layer_tree_host()->AddSurfaceLayerId(*new_surface_id);
+    }
   }
   UpdateDrawsContent(HasDrawableContent());
   SetNeedsCommit();
 }
 
 void SurfaceLayer::SetFallbackSurfaceInfo(const SurfaceInfo& surface_info) {
+  const SurfaceId* old_surface_id =
+      GetReferencedSurfaceId(fallback_surface_info_);
   RemoveReference(std::move(fallback_reference_returner_));
   fallback_surface_info_ = surface_info;
   if (layer_tree_host()) {
     fallback_reference_returner_ = ref_factory_->CreateReference(
         layer_tree_host(), fallback_surface_info_.id());
+    const SurfaceId* new_surface_id =
+        GetReferencedSurfaceId(fallback_surface_info_);
+    if (old_surface_id != new_surface_id) {
+      if (old_surface_id)
+        layer_tree_host()->RemoveSurfaceLayerId(*old_surface_id);
+      if (new_surface_id)
+        layer_tree_host()->AddSurfaceLayerId(*new_surface_id);
+    }
   }
   SetNeedsCommit();
 }
@@ -104,6 +129,17 @@ void SurfaceLayer::SetLayerTreeHost(LayerTreeHost* host) {
     Layer::SetLayerTreeHost(host);
     return;
   }
+  const SurfaceId* primary_surface_id =
+      GetReferencedSurfaceId(primary_surface_info_);
+  const SurfaceId* fallback_surface_id =
+      GetReferencedSurfaceId(fallback_surface_info_);
+
+  if (layer_tree_host()) {
+    if (primary_surface_id)
+      layer_tree_host()->RemoveSurfaceLayerId(*primary_surface_id);
+    if (fallback_surface_id)
+      layer_tree_host()->RemoveSurfaceLayerId(*fallback_surface_id);
+  }
   RemoveReference(std::move(primary_reference_returner_));
   RemoveReference(std::move(fallback_reference_returner_));
   Layer::SetLayerTreeHost(host);
@@ -116,6 +152,10 @@ void SurfaceLayer::SetLayerTreeHost(LayerTreeHost* host) {
       fallback_reference_returner_ = ref_factory_->CreateReference(
           layer_tree_host(), fallback_surface_info_.id());
     }
+    if (primary_surface_id)
+      layer_tree_host()->AddSurfaceLayerId(*primary_surface_id);
+    if (fallback_surface_id)
+      layer_tree_host()->RemoveSurfaceLayerId(*fallback_surface_id);

[enne (OOO), 2017/05/24 21:57:42]

add?

[jaydasika, 2017/05/24 22:12:56]

Done.

   }
 }