Introducing SurfaceReferenceFactory

cc/surfaces/surface_reference_base.h

+// 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.
+
+#ifndef CC_SURFACES_SURFACE_REFERENCE_BASE_H_
+#define CC_SURFACES_SURFACE_REFERENCE_BASE_H_
+
+#include <memory>
+
+#include "base/memory/ptr_util.h"
+#include "cc/surfaces/surface_reference_factory.h"
+#include "cc/surfaces/surface_sequence.h"
+
+namespace cc {
+
+class CompositorFrameMetadata;
+class SurfaceReferenceFactory;
+
+/* The base class for the references returned by SurfaceReferenceFactory and
+ * its subclasses.
+ * The objects of this class hold on to their corresponding surface reference
+ * until destroy is called or until the object goes out of scope.
+ * To keep things as lightweight as possible, the base class only keeps a
+ * pointer to the factory and it's left up to the subclasses to decide what
+ * other information they need to keep. */
+class SurfaceReferenceBase {
+ public:
+  explicit SurfaceReferenceBase(const SurfaceReferenceFactory* factory);

[Fady Samuel, 2016/12/12 22:35:26]

If you're holding onto SurfaceReferenceFactory as a scoped_refptr, then take it
in as a scoped_refptr. So:

SurfaceReferenceBase(scoped_refptr<SurfaceReferenceFactory> factory);

+  virtual ~SurfaceReferenceBase();
+
+  void Destroy();
+  void Destroy(CompositorFrameMetadata* metadata);
+  bool IsDestroyed() const;

[Fady Samuel, 2016/12/12 22:35:26]

bool destroyed() const { return !!factory_; }

+
+  const SurfaceReferenceFactory* factory() const { return factory_.get(); }
+
+ private:
+  scoped_refptr<const SurfaceReferenceFactory> factory_;
+};
+
+}  // namespace cc
+
+#endif  // CC_SURFACES_SURFACE_REFERENCE_BASE_H_