Introducing SurfaceReferenceFactory

cc/surfaces/sequence_surface_reference_factory.cc

+// Copyright 2016 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/sequence_surface_reference_factory.h"
+
+#include "cc/surfaces/sequence_surface_reference.h"
+
+namespace cc {
+
+std::unique_ptr<SurfaceReferenceBase>
+SequenceSurfaceReferenceFactory::CreateReference(
+    SurfaceReferenceOwner* owner,
+    const SurfaceId& surface_id) const {
+  auto seq = owner->GetSurfaceSequenceGenerator()->CreateSurfaceSequence();
+  RequireSequence(surface_id, seq);
+  return base::MakeUnique<SequenceSurfaceReference>(make_scoped_refptr(this),
+                                                    seq);
+}
+
+void SequenceSurfaceReferenceFactory::DestroyReference(
+    SurfaceReferenceBase* surface_ref,
+    CompositorFrameMetadata* metadata) const {
+  // The surface reference was generated by this factory, so we can cast it
+  // to the type we returned in CreateReference.

[Fady Samuel, 2016/12/13 22:55:05]

nit; You should mention that SurfaceReference is a friend 

[Saman Sami, 2016/12/14 17:50:01]

Done.

+  auto ref = static_cast<SequenceSurfaceReference*>(surface_ref);
+  metadata->satisfies_sequences.push_back(ref->sequence().sequence);
+}
+
+void SequenceSurfaceReferenceFactory::DestroyReference(
+    SurfaceReferenceBase* surface_ref) const {
+  // The surface reference was generated by this factory, so we can cast it
+  // to the type we returned in CreateReference.

[Fady Samuel, 2016/12/13 22:55:05]

nit; You should mention that SurfaceReference is a friend 

[Saman Sami, 2016/12/14 17:50:01]

Done.

+  auto ref = static_cast<SequenceSurfaceReference*>(surface_ref);
+  SatisfySequence(ref->sequence());
+}
+
+}  // namespace cc