[PPAPI] Implement media stream video track API

ppapi/proxy/media_stream_track_resource_base.h

+// Copyright (c) 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 PPAPI_PROXY_MEDIA_STREAM_TRACK_RESOURCE_BASE_H_
+#define PPAPI_PROXY_MEDIA_STREAM_TRACK_RESOURCE_BASE_H_
+
+#include "ppapi/proxy/plugin_resource.h"
+#include "ppapi/proxy/ppapi_proxy_export.h"
+#include "ppapi/shared_impl/media_stream_frame_buffer.h"
+
+namespace ppapi {
+namespace proxy {
+
+class PPAPI_PROXY_EXPORT MediaStreamTrackResourceBase
+  : public PluginResource,
+    public MediaStreamFrameBuffer::Delegate {
+ protected:
+  MediaStreamTrackResourceBase(Connection connection,
+                               PP_Instance instance,
+                               int pending_renderer_id,
+                               const std::string& id);
+
+  virtual ~MediaStreamTrackResourceBase();
+
+  std::string id() const { return id_; }
+
+  bool has_ended() const { return has_ended_; }
+
+  MediaStreamFrameBuffer* frame_buffer() { return &frame_buffer_; }
+
+  void CloseInternal();
+
+  // Sends a frame index to the corresponding PepperMediaStreamTrackHostBase
+  // via an IPC message. The host adds the frame index into its
+  // |frame_buffer_| for reading or writing. Also see |MediaStreamFrameBuffer|.
+  void SendEnqueueFrameMessageToHost(int32_t index);
+
+  // PluginResource overrides:
+  virtual void OnReplyReceived(const ResourceMessageReplyParams& params,
+                               const IPC::Message& msg) OVERRIDE;
+
+ private:
+  // Message handlers:
+  void OnPluginMsgInitFrames(const ResourceMessageReplyParams& params,
+                             int32_t number_of_frames,
+                             int32_t frame_size);
+  void OnPluginMsgEnqueueFrame(const ResourceMessageReplyParams& params,
+                               int32_t index);
+
+  MediaStreamFrameBuffer frame_buffer_;
+
+  std::string id_;
+
+  bool has_ended_;
+
+  DISALLOW_COPY_AND_ASSIGN(MediaStreamTrackResourceBase);
+};
+
+}  // namespace proxy
+}  // namespace ppapi
+
+#endif  // PPAPI_PROXY_MEDIA_STREAM_TRACK_RESOURCE_BASE_H_