blimp: Move BlimpCompositor to use delegated rendering.

blimp/client/core/compositor/output_surface_proxy.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 BLIMP_CLIENT_CORE_COMPOSITOR_OUTPUT_SURFACE_PROXY_H_
+#define BLIMP_CLIENT_CORE_COMPOSITOR_OUTPUT_SURFACE_PROXY_H_
+
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "cc/resources/returned_resource.h"
+
+namespace cc {
+class CompositorFrame;
+}
+
+namespace blimp {
+namespace client {
+
+// The client is the class for the proxy to interact with the cc::OutputSurface.
+// It should only be called on the compositor thread.
+class OutputSurfaceProxyClient {
+ public:
+  virtual ~OutputSurfaceProxyClient() {}
+
+  // Sent when the compositor can safely reclaim the |resources| references in
+  // a compositor frame.
+  virtual void ReclaimCompositorResources(
+      const cc::ReturnedResourceArray& resources) = 0;
+};
+
+// This class is meant to be a proxy for the OutputSurface to interact with the
+// consumer of the CompositorFrames. All calls to the OutputSurfaceProxy are
+// made on the thread on which proxy exists.
+class OutputSurfaceProxy {
+ public:
+  virtual ~OutputSurfaceProxy() {}
+
+  // Will be called when the cc::OutputSurface is bound to its client on the
+  // compositor thread. The weak ptr to the client can be used to post messages
+  // to it on the compositor thread. This *must* be called before any messages
+  // are sent to the proxy.
+  virtual void BindToClient(base::WeakPtr<OutputSurfaceProxyClient> client) = 0;
+
+  // The implementation should take the contents of the compositor frame and
+  // return the referenced resources when the frame is no longer being draw
+  // using OutputSurfaceProxyClient::ReclaimCompositorResources.
+  virtual void SwapCompositorFrame(cc::CompositorFrame frame) = 0;
+
+  // Will be called when the cc::OutputSurface detaches itself from its client
+  // on the compositor thread. Any messages sent to the client beyond this point
+  // will be silently dropped and no more messages can be sent to the proxy
+  // going forward.
+  virtual void DetachFromClient() = 0;
+};
+
+}  // namespace client
+}  // namespace blimp
+
+#endif  // BLIMP_CLIENT_CORE_COMPOSITOR_OUTPUT_SURFACE_PROXY_H_