Introducing SurfaceReferenceFactory

cc/surfaces/surface_embedding_base.h

+// Copyright (c) 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_EMBEDDING_BASE_H_
+#define CC_SURFACES_SURFACE_EMBEDDING_BASE_H_
+
+#include <memory>
+
+#include "base/memory/ptr_util.h"
+#include "cc/surfaces/surface_id.h"
+#include "cc/surfaces/surface_sequence.h"
+#include "cc/surfaces/surface_sequence_generator.h"
+#include "ui/gfx/geometry/size.h"
+
+namespace cc {
+
+struct SurfaceInfo {
+  SurfaceId id;
+  float scale = 1.f;
+  gfx::Size size;
+
+  SurfaceInfo() {}
+  SurfaceInfo(const SurfaceId& id, float scale, gfx::Size size)
+      : id(id), scale(scale), size(size) {}
+  bool operator==(const SurfaceInfo& info) const {
+    return id == info.id && scale == info.scale && size == info.size;
+  }
+};
+
+class CompositorFrameMetadata;
+class SurfaceEmbedding;
+typedef std::unique_ptr<SurfaceEmbedding> SurfaceEmbeddingPtr;
+
+class SurfaceEmbeddingOwner {
+ public:
+  virtual SurfaceSequenceGenerator* GetSurfaceSequenceGenerator() = 0;
+};
+
+class SurfaceRef;
+typedef std::unique_ptr<SurfaceRef> SurfaceRefPtr;
+
+class SurfaceRef final {

[Fady Samuel, 2016/12/12 16:11:59]

Make this move only and create on stack. Call it ScopedSurfaceReference

+ public:
+  void Destroy();
+  void Destroy(CompositorFrameMetadata* metadata);
+  ~SurfaceRef();
+
+ private:
+  friend class SurfaceEmbedding;
+  explicit SurfaceRef(SurfaceEmbeddingPtr embedding);
+  bool is_deleted_ = false;

[Fady Samuel, 2016/12/12 16:11:59]

What's the point of this? Set embedding_ = nullptr instead?

+  SurfaceEmbeddingPtr embedding_;
+};
+
+class SurfaceEmbedding {

[Fady Samuel, 2016/12/12 16:11:59]

Make this refcounted.

+ public:
+  explicit SurfaceEmbedding(const SurfaceInfo& info) : info_(info) {}
+
+  SurfaceRefPtr CreateReference(SurfaceEmbeddingOwner* owner) const {
+    SurfaceEmbeddingPtr clone = Clone();
+    clone->owner_ = owner;
+    return SurfaceRefPtr(new SurfaceRef(std::move(clone)));
+  }
+
+  const SurfaceInfo& info() const { return info_; }
+  const SurfaceId& id() const { return info_.id; }
+  float scale() const { return info_.scale; }
+  const gfx::Size& size() const { return info_.size; }
+
+  SurfaceEmbeddingPtr Clone() const { return SurfaceEmbeddingPtr(CloneImpl()); }
+
+ protected:
+  SurfaceEmbeddingOwner* owner() { return owner_; }
+
+ private:
+  virtual void AddReference() = 0;
+  virtual void RemoveReference() = 0;
+  virtual void RemoveReference(CompositorFrameMetadata*) = 0;
+  virtual SurfaceEmbedding* CloneImpl() const = 0;
+
+  const SurfaceInfo info_;
+  SurfaceEmbeddingOwner* owner_ = nullptr;
+
+  friend class SurfaceRef;
+};
+
+}  // namespace cc
+
+#endif  // CC_SURFACES_SURFACE_EMBEDDING_BASE_H_