Add/remove surface references via MojoCompositorFrameSink.

services/ui/surfaces/display_compositor.cc

Index: services/ui/surfaces/display_compositor.cc
diff --git a/services/ui/surfaces/display_compositor.cc b/services/ui/surfaces/display_compositor.cc
index 51ce69ef70fd532c6d8c374afea0663f3ac74bf7..9a53712cd6ab385293e2c9645bff488e1e0b4e8f 100644
--- a/services/ui/surfaces/display_compositor.cc
+++ b/services/ui/surfaces/display_compositor.cc
@@ -29,6 +29,8 @@ DisplayCompositor::DisplayCompositor(
       reference_manager_(&manager_),
       binding_(this, std::move(request)) {
   manager_.AddObserver(this);
+  if (client_)
+    client_->OnRootSurfaceId(GetRootSurfaceId());
 }
 
 void DisplayCompositor::CreateCompositorFrameSink(
@@ -54,18 +56,16 @@ void DisplayCompositor::CreateCompositorFrameSink(
           std::move(private_request), std::move(client));
 }
 
-void DisplayCompositor::AddRootSurfaceReference(const cc::SurfaceId& child_id) {
-  AddSurfaceReference(GetRootSurfaceId(), child_id);
-}
+void DisplayCompositor::AddSurfaceReference(const cc::SurfaceReference& ref) {
+  const cc::SurfaceId& parent_id = ref.parent_id();
+  const cc::SurfaceId& child_id = ref.child_id();
 
-void DisplayCompositor::AddSurfaceReference(const cc::SurfaceId& parent_id,
-                                            const cc::SurfaceId& child_id) {
   auto vector_iter = temp_references_.find(child_id.frame_sink_id());
 
   // If there are no temporary references for the FrameSinkId then we can just
   // add reference and return.
   if (vector_iter == temp_references_.end()) {
-    reference_manager_->AddSurfaceReference(parent_id, child_id);
+    CHECK(reference_manager_->AddSurfaceReference(parent_id, child_id));
     return;
   }
 
@@ -77,7 +77,7 @@ void DisplayCompositor::AddSurfaceReference(const cc::SurfaceId& parent_id,
       std::find(refs.begin(), refs.end(), child_id.local_frame_id());
 
   if (temp_ref_iter == refs.end()) {
-    reference_manager_->AddSurfaceReference(parent_id, child_id);
+    CHECK(reference_manager_->AddSurfaceReference(parent_id, child_id));
     return;
   }
 
@@ -85,8 +85,9 @@ void DisplayCompositor::AddSurfaceReference(const cc::SurfaceId& parent_id,
   // wants to add a reference to the top level root then we do nothing.
   // Otherwise remove the temporary reference and add the reference.
   if (parent_id != GetRootSurfaceId()) {
-    reference_manager_->AddSurfaceReference(parent_id, child_id);
-    reference_manager_->RemoveSurfaceReference(GetRootSurfaceId(), child_id);
+    CHECK(reference_manager_->AddSurfaceReference(parent_id, child_id));
+    CHECK(reference_manager_->RemoveSurfaceReference(GetRootSurfaceId(),
+                                                     child_id));
   }
 
   // Remove temporary references for surfaces with the same FrameSinkId that
@@ -95,7 +96,7 @@ void DisplayCompositor::AddSurfaceReference(const cc::SurfaceId& parent_id,
   // parent doesn't need them anymore.
   for (auto iter = refs.begin(); iter != temp_ref_iter; ++iter) {
     cc::SurfaceId id = cc::SurfaceId(child_id.frame_sink_id(), *iter);
-    reference_manager_->RemoveSurfaceReference(GetRootSurfaceId(), id);
+    CHECK(reference_manager_->RemoveSurfaceReference(GetRootSurfaceId(), id));
   }
 
   // Remove markers for temporary references up to |child_id|, as the temporary
@@ -108,16 +109,12 @@ void DisplayCompositor::AddSurfaceReference(const cc::SurfaceId& parent_id,
     refs.erase(refs.begin(), ++temp_ref_iter);
 }
 
-void DisplayCompositor::RemoveRootSurfaceReference(
-    const cc::SurfaceId& child_id) {
-  RemoveSurfaceReference(GetRootSurfaceId(), child_id);
-}
-
-void DisplayCompositor::RemoveSurfaceReference(const cc::SurfaceId& parent_id,
-                                               const cc::SurfaceId& child_id) {
+void DisplayCompositor::RemoveSurfaceReference(
+    const cc::SurfaceReference& ref) {
   // TODO(kylechar): Each remove reference can trigger GC, it would be better if
   // we GC only once if removing multiple references.
-  reference_manager_->RemoveSurfaceReference(parent_id, child_id);
+  CHECK(reference_manager_->RemoveSurfaceReference(ref.parent_id(),
+                                                   ref.child_id()));
 }
 
 DisplayCompositor::~DisplayCompositor() {