Add in a new FrameConsumer interface, Decode API, and a RectangleUpdateDecoder abstraction.

remoting/client/frame_consumer.h

+// Copyright (c) 2010 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 REMOTING_CLIENT_FRAME_CONSUMER_H_
+#define REMOTING_CLIENT_FRAME_CONSUMER_H_
+
+namespace remoting {
+
+class FrameConsumer {
+ public:
+  FrameConsumer() {}
+  virtual ~FrameConsumer() {}
+
+  // Request a frame be allocated from the FrameConsumer.
+  //
+  // If a frame cannot be allocated to fit the format, and height/width
+  // requirements, |frame_out| will be set to NULL.
+  //
+  // An allocated frame will have at least the width and height requested, but
+  // may be bigger. Query the retrun frame for the actual frame size, stride,
+  // etc.
+  //
+  // The AllocateFrame call is asynchronous.  From invocation, until when the
+  // |done| callback is invoked, |frame_out| should be considered to be locked
+  // by the FrameConsumer, must remain a valid pointer, and should not be
+  // examined or modified.  After |done| is called, the |frame_out| will
+  // contain a result of the allocation. If a frame could not be allocated,
+  // |frame_out| will be NULL.
+  //
+  // All frames retrieved via the AllocateFrame call must be released by a
+  // corresponding call ReleaseFrame(scoped_refptr<VideoFrame>* frame_out.
+  virtual void AllocateFrame(media::VideoFrame::Format format,
+                             size_t width,
+                             size_t height,
+                             base::TimeDelta timestamp,
+                             base::TimeDelta duration,
+                             scoped_refptr<media::VideoFrame>* frame_out,
+                             Task* done) = 0;
+
+  virtual void ReleaseFrame(media::VideoFrame* frame) = 0;
+
+  // OnPartialFrameOutput() is called every time at least one rectangle of
+  // output is produced.  The |frame| is guaranteed to have valid data for
+  // every region included in the |rects| list.
+  //
+  // Both |frame| and |rects| are guaranteed to be valid until the |done|
+  // callback is invoked.
+  virtual void OnPartialFrameOutput(media::VideoFrame* frame,
+                                    UpdatedRects* rects,
+                                    Task* done) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(FrameConsumer);
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_CLIENT_FRAME_CONSUMER_H_