Moving temporary reference logic to SurfaceManager

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 35c92cd31db5df72c58eea5c23a44c971aeff84a..8f30e7fb6ef8fc6536e73a7725325439497aa550 100644
--- a/services/ui/surfaces/display_compositor.cc
+++ b/services/ui/surfaces/display_compositor.cc
@@ -24,7 +24,7 @@
 #include "services/ui/surfaces/display_output_surface_ozone.h"
 #endif
 
-    namespace ui {
+namespace ui {
 
 DisplayCompositor::DisplayCompositor(
     scoped_refptr<gpu::InProcessCommandBuffer::Service> gpu_service,
@@ -48,8 +48,10 @@ DisplayCompositor::DisplayCompositor(
 void DisplayCompositor::AddSurfaceReferences(
     const std::vector<cc::SurfaceReference>& references) {
   DCHECK(thread_checker_.CalledOnValidThread());
-  for (auto& reference : references)
-    AddSurfaceReference(reference);
+  for (const auto& reference : references) {
+    reference_manager_->AddSurfaceReference(reference.parent_id(),
+                                            reference.child_id());
+  }
 }
 
 void DisplayCompositor::RemoveSurfaceReferences(
@@ -58,20 +60,14 @@ void DisplayCompositor::RemoveSurfaceReferences(
 
   // TODO(kylechar): Each remove reference can trigger GC, it would be better if
   // we GC only once if removing multiple references.
-  for (auto& reference : references)
-    RemoveSurfaceReference(reference);
+  for (const auto& reference : references) {
+    reference_manager_->RemoveSurfaceReference(reference.parent_id(),
+                                               reference.child_id());
+  }
 }
 
 DisplayCompositor::~DisplayCompositor() {
   DCHECK(thread_checker_.CalledOnValidThread());
-  // Remove all temporary references on shutdown.
-  for (auto& map_entry : temp_references_) {
-    const cc::FrameSinkId& frame_sink_id = map_entry.first;
-    for (auto& local_frame_id : map_entry.second) {
-      reference_manager_->RemoveSurfaceReference(
-          GetRootSurfaceId(), cc::SurfaceId(frame_sink_id, local_frame_id));
-    }
-  }
   manager_.RemoveObserver(this);
 }
 
@@ -126,63 +122,6 @@ void DisplayCompositor::CreateOffscreenCompositorFrameSink(
                                     std::move(client), nullptr);
 }
 
-void DisplayCompositor::AddSurfaceReference(const cc::SurfaceReference& ref) {
-  const cc::SurfaceId& parent_id = ref.parent_id();
-  const cc::SurfaceId& child_id = ref.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);
-    return;
-  }
-
-  // Get the vector<LocalFrameId> for the appropriate FrameSinkId and look for
-  // |child_id.local_frame_id| in that vector. If found, there is a temporary
-  // reference to |child_id|.
-  std::vector<cc::LocalFrameId>& refs = vector_iter->second;
-  auto temp_ref_iter =
-      std::find(refs.begin(), refs.end(), child_id.local_frame_id());
-
-  if (temp_ref_iter == refs.end()) {
-    reference_manager_->AddSurfaceReference(parent_id, child_id);
-    return;
-  }
-
-  // All surfaces get a temporary reference to the top level root. If the parent
-  // 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);
-  }
-
-  // Remove temporary references for surfaces with the same FrameSinkId that
-  // were created before |child_id|. The earlier surfaces were never embedded in
-  // the parent and the parent is embedding a later surface, so we know the
-  // 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);
-  }
-
-  // Remove markers for temporary references up to |child_id|, as the temporary
-  // references they correspond to were removed above. If |temp_ref_iter| points
-  // at the last element in |refs| then we are removing all temporary references
-  // for the FrameSinkId and can remove the map entry entirely.
-  if (++temp_ref_iter == refs.end())
-    temp_references_.erase(child_id.frame_sink_id());
-  else
-    refs.erase(refs.begin(), temp_ref_iter);
-}
-
-void DisplayCompositor::RemoveSurfaceReference(
-    const cc::SurfaceReference& ref) {
-  reference_manager_->RemoveSurfaceReference(ref.parent_id(), ref.child_id());
-}
-
 std::unique_ptr<cc::Display> DisplayCompositor::CreateDisplay(
     const cc::FrameSinkId& frame_sink_id,
     gpu::SurfaceHandle surface_handle,
@@ -254,16 +193,6 @@ const cc::SurfaceId& DisplayCompositor::GetRootSurfaceId() const {
 void DisplayCompositor::OnSurfaceCreated(const cc::SurfaceInfo& surface_info) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK_GT(surface_info.device_scale_factor(), 0.0f);
-  // We can get into a situation where multiple CompositorFrames arrive for a
-  // CompositorFrameSink before the DisplayCompositorClient can add any
-  // references for the frame. When the second frame with a new size arrives,
-  // the first will be destroyed and then if there are no references it will be
-  // deleted during surface GC. A temporary reference, removed when a real
-  // reference is received, is added to prevent this from happening.
-  reference_manager_->AddSurfaceReference(GetRootSurfaceId(),
-                                          surface_info.id());
-  temp_references_[surface_info.id().frame_sink_id()].push_back(
-      surface_info.id().local_frame_id());
 
   if (client_)
     client_->OnSurfaceCreated(surface_info);