Add a simple compositor for Sky

sky/compositor/layer.h

Index: sky/compositor/layer.h
diff --git a/sky/compositor/layer.h b/sky/compositor/layer.h
new file mode 100644
index 0000000000000000000000000000000000000000..94925278652b7e33146d2c5dae537b8f741d9438
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+++ b/sky/compositor/layer.h
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+// 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.
+
+#ifndef SKY_COMPOSITOR_LAYER_H_
+#define SKY_COMPOSITOR_LAYER_H_
+
+#include "base/memory/ref_counted.h"
+#include "mojo/gpu/gl_texture.h"
+#include "sky/compositor/layer_client.h"
+#include "ui/gfx/geometry/rect.h"
+
+namespace sky {
+class LayerHost;
+
+class Layer : public base::RefCounted<Layer> {
+ public:
+  explicit Layer(LayerClient* client);
+
+  void ClearClient();
+
+  void SetSize(const gfx::Size& size);
+  void Display();
+
+  scoped_ptr<mojo::GLTexture> GetTexture();
+
+  const gfx::Size& size() const { return size_; }
+
+  void set_host(LayerHost* host) { host_ = host; }
+
+ private:
+  friend class base::RefCounted<Layer>;
+  ~Layer();
+
+  LayerClient* client_;
+  LayerHost* host_;
+  gfx::Size size_;
+
+  scoped_ptr<mojo::GLTexture> texture_;
+
+  DISALLOW_COPY_AND_ASSIGN(Layer);
+};
+
+}  // namespace sky
+
+#endif  // SKY_COMPOSITOR_LAYER_H_