Add DisplayCompositorTest.

services/ui/surfaces/display_compositor.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "services/ui/surfaces/display_compositor.h"
 
 #include "cc/surfaces/surface.h"
 
 namespace ui {
 
 DisplayCompositor::DisplayCompositor(
     cc::mojom::DisplayCompositorClientPtr client)
-    : client_(std::move(client)) {
+    : client_(std::move(client)),
+      reference_manager_(&manager_),
+      root_surface_id_(reference_manager_->GetRootSurfaceId()) {
   manager_.AddObserver(this);
 }
 
 void DisplayCompositor::AddRootSurfaceReference(const cc::SurfaceId& child_id) {
   AddSurfaceReference(manager_.GetRootSurfaceId(), 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()) {
-    manager_.AddSurfaceReference(parent_id, child_id);
+    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()) {
-    manager_.AddSurfaceReference(parent_id, child_id);
+    reference_manager_->AddSurfaceReference(parent_id, child_id);
     return;
   }
 
   // All surfaces get a temporary reference to the top level root. If we want to
   // add a real reference to the top level root then we do nothing. Otherwise
   // remove the temporary reference and add the real reference.
-  if (parent_id != manager_.GetRootSurfaceId()) {
-    manager_.AddSurfaceReference(parent_id, child_id);
-    manager_.RemoveSurfaceReference(manager_.GetRootSurfaceId(), child_id);
+  if (parent_id != root_surface_id_) {
+    reference_manager_->AddSurfaceReference(parent_id, child_id);
+    reference_manager_->RemoveSurfaceReference(root_surface_id_, 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);
-    manager_.RemoveSurfaceReference(manager_.GetRootSurfaceId(), id);
+    reference_manager_->RemoveSurfaceReference(root_surface_id_, id);
   }
 
   // Remove markers for temporary references up to |child_id|, as the temporary
   // references they correspond to were removed above. If |ref_iter| is 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::RemoveRootSurfaceReference(
     const cc::SurfaceId& child_id) {
-  RemoveSurfaceReference(manager_.GetRootSurfaceId(), child_id);
+  RemoveSurfaceReference(root_surface_id_, child_id);
 }
 
 void DisplayCompositor::RemoveSurfaceReference(const cc::SurfaceId& parent_id,
                                                const cc::SurfaceId& child_id) {
   // TODO(kylechar): Each remove reference can trigger GC, it would be better if
   // we GC only once if removing multiple references.
-  manager_.RemoveSurfaceReference(parent_id, child_id);
+  reference_manager_->RemoveSurfaceReference(parent_id, child_id);
 }
 
 DisplayCompositor::~DisplayCompositor() {
   // 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) {
-      manager_.RemoveSurfaceReference(
-          manager_.GetRootSurfaceId(),
-          cc::SurfaceId(frame_sink_id, local_frame_id));
+      reference_manager_->RemoveSurfaceReference(
+          root_surface_id_, cc::SurfaceId(frame_sink_id, local_frame_id));
     }
   }
   manager_.RemoveObserver(this);
 }
 
 void DisplayCompositor::OnSurfaceCreated(const cc::SurfaceId& surface_id,
                                          const gfx::Size& frame_size,
                                          float device_scale_factor) {
   // 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.
-  manager_.AddSurfaceReference(manager_.GetRootSurfaceId(), surface_id);
+  reference_manager_->AddSurfaceReference(root_surface_id_, surface_id);
   temp_references_[surface_id.frame_sink_id()].push_back(
       surface_id.local_frame_id());
 
   if (client_)
     client_->OnSurfaceCreated(surface_id, frame_size, device_scale_factor);
 }
 
 void DisplayCompositor::OnSurfaceDamaged(const cc::SurfaceId& surface_id,
                                          bool* changed) {}
 
 }  // namespace ui