Decouple GpuCompositorFrameSink from DisplayCompositor

cc/surfaces/surface_manager.cc

 // Copyright 2014 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 "cc/surfaces/surface_manager.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <queue>
@@ skipping 206 matching lines @@
       parent_to_child_refs_[parent_id].count(child_id) == 0) {
     DLOG(ERROR) << "No reference from " << parent_id.ToString() << " to "
                 << child_id.ToString();
     return;
   }
 
   RemoveSurfaceReferenceImpl(parent_id, child_id);
   GarbageCollectSurfaces();
 }
 
+void SurfaceManager::AddSurfaceReferences(
+    const std::vector<SurfaceReference>& references) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  for (const auto& reference : references) {

[kylechar, 2017/01/25 15:54:33]

Get rid of {} since the loop body is only one line.

+    AddSurfaceReference(reference.parent_id(), reference.child_id());
+  }
+}
+
+void SurfaceManager::RemoveSurfaceReferences(
+    const std::vector<SurfaceReference>& references) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  // TODO(kylechar): Each remove reference can trigger GC, it would be better if

[kylechar, 2017/01/25 15:54:33]

We can easily make this comment a reality now. Run GarbageCollectSurfaces() once
after you go through the list of references to remove and remove the call from
GarbageCollectSurfaces().

+  // we GC only once if removing multiple references.
+  for (const auto& reference : references) {

[kylechar, 2017/01/25 15:54:33]

Get rid of {} since the loop body is only one line.

+    RemoveSurfaceReference(reference.parent_id(), reference.child_id());
+  }
+}
+
 size_t SurfaceManager::GetSurfaceReferenceCount(
     const SurfaceId& surface_id) const {
   auto iter = child_to_parent_refs_.find(surface_id);
   if (iter == child_to_parent_refs_.end())
     return 0;
   return iter->second.size();
 }
 
 size_t SurfaceManager::GetReferencedSurfaceCount(
     const SurfaceId& surface_id) const {
@@ skipping 389 matching lines @@
     std::vector<SurfaceId> children(iter->second.begin(), iter->second.end());
     std::sort(children.begin(), children.end());
 
     for (const SurfaceId& child_id : children)
       SurfaceReferencesToStringImpl(child_id, indent + "  ", str);
   }
 }
 #endif  // DCHECK_IS_ON()
 
 }  // namespace cc