Add the frame provider base class used in cast media.

chromecast/media/cma/filters/demuxer_stream_adapter.h

Index: chromecast/media/cma/filters/demuxer_stream_adapter.h
diff --git a/chromecast/media/cma/filters/demuxer_stream_adapter.h b/chromecast/media/cma/filters/demuxer_stream_adapter.h
new file mode 100644
index 0000000000000000000000000000000000000000..f7c91606f835776bbeca06c7d47a9929f0528913
--- /dev/null
+++ b/chromecast/media/cma/filters/demuxer_stream_adapter.h
@@ -0,0 +1,85 @@
+// 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 CHROMECAST_MEDIA_CMA_FILTERS_DEMUXER_STREAM_ADAPTER_H_
+#define CHROMECAST_MEDIA_CMA_FILTERS_DEMUXER_STREAM_ADAPTER_H_
+
+#include "base/callback.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "base/threading/thread_checker.h"
+#include "base/time/time.h"
+#include "chromecast/media/cma/base/coded_frame_provider.h"
+#include "media/base/audio_decoder_config.h"
+#include "media/base/demuxer_stream.h"
+#include "media/base/video_decoder_config.h"
+
+namespace base {
+class SingleThreadTaskRunner;
+}
+
+namespace media {
+class DemuxerStream;
+}
+
+namespace chromecast {
+namespace media {
+class BalancedMediaTaskRunnerFactory;
+class MediaTaskRunner;
+
+// DemuxerStreamAdapter wraps a DemuxerStream into a CodedFrameProvider.
+class DemuxerStreamAdapter : public CodedFrameProvider {
+ public:
+  DemuxerStreamAdapter(
+      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
+      const scoped_refptr<BalancedMediaTaskRunnerFactory>&
+      media_task_runner_factory,
+      ::media::DemuxerStream* demuxer_stream);
+  virtual ~DemuxerStreamAdapter();
+
+  // CodedFrameProvider implementation.
+  virtual void Read(const ReadCb& read_cb) OVERRIDE;
+  virtual void Flush(const base::Closure& flush_cb) OVERRIDE;
+
+ private:
+  void ResetMediaTaskRunner();
+
+  void RequestBuffer(const ReadCb& read_cb);
+
+  // Callback invoked from the demuxer stream to signal a buffer is ready.
+  void OnNewBuffer(const ReadCb& read_cb,
+                   ::media::DemuxerStream::Status status,
+                   const scoped_refptr< ::media::DecoderBuffer>& input);
+
+  base::ThreadChecker thread_checker_;
+
+  // Task runner DemuxerStreamAdapter is running on.
+  scoped_refptr<base::SingleThreadTaskRunner> const task_runner_;
+
+  // Media task runner to pace requests to the DemuxerStream.
+  scoped_refptr<BalancedMediaTaskRunnerFactory> const
+      media_task_runner_factory_;
+  scoped_refptr<MediaTaskRunner> media_task_runner_;
+  base::TimeDelta max_pts_;
+
+  // Frames are provided by |demuxer_stream_|.
+  ::media::DemuxerStream* const demuxer_stream_;
+
+  // Indicate if there is a pending read on the demuxer.
+  bool is_pending_read_;
+
+  // Audio/video configuration that applies to the next frame.
+  ::media::AudioDecoderConfig audio_config_;
+  ::media::VideoDecoderConfig video_config_;
+
+  scoped_ptr<base::WeakPtrFactory<DemuxerStreamAdapter> > weak_factory_;
+  base::WeakPtr<DemuxerStreamAdapter> weak_this_;
+
+  DISALLOW_COPY_AND_ASSIGN(DemuxerStreamAdapter);
+};
+
+}  // namespace media
+}  // namespace chromecast
+
+#endif  // CHROMECAST_MEDIA_CMA_FILTERS_DEMUXER_STREAM_ADAPTER_H_