Prototype: NativeLayer renderer with GL fallback

cc/output/renderer_chain.h

+// Copyright 2015 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_OUTPUT_RENDERER_CHAIN_H_
+#define CC_OUTPUT_RENDERER_CHAIN_H_
+
+#include "cc/base/scoped_ptr_vector.h"
+#include "cc/output/renderer.h"
+
+namespace cc {
+
+class CC_EXPORT RendererChain : public Renderer {
+ public:
+  static scoped_ptr<RendererChain> Create();
+  ~RendererChain() override;
+
+  void AddRenderer(scoped_ptr<Renderer> renderer);
+
+  // Renderer overrides.
+  const RendererCapabilitiesImpl& Capabilities() const override;
+  void DecideRenderPassAllocationsForFrame(
+      const RenderPassList& render_passes) override;
+  void DrawFrame(RenderPassList* render_passes_,
+                 float scale_factor,
+                 const gfx::Rect& viewport_rect,
+                 const gfx::Rect& clip_rect,
+                 bool disable_picture_quad_image_filtering) override;
+  void Finish() override;
+  void SwapBuffers(const CompositorFrameMetadata& metadata) override;
+
+ protected:
+  RendererChain();
+
+  // Renderer overrides.
+  void DidChangeVisibility() override;
+
+ private:
+  ScopedPtrVector<Renderer> renderers_;
+  Renderer* active_renderer_;
+
+  DISALLOW_COPY_AND_ASSIGN(RendererChain);
+};
+
+}  // namespace cc
+
+#endif  // CC_OUTPUT_RENDERER_CHAIN_H_