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

remoting/base/decoder.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_BASE_DECODER_H_
 #define REMOTING_BASE_DECODER_H_
 
 #include <vector>
 
 #include "base/task.h"
@@ skipping 72 matching lines @@
   // decoder should also call |decode_done_| as soon as possible.
   virtual void EndDecode() = 0;
 
   // Return the encoding type that this decoder handles.
   virtual UpdateStreamEncoding Encoding() { return encoding_; }
 
   // Return the current state of the decoder: 'true' if we're in the middle
   // of BeginDecode() / EndDecode().
   virtual bool IsStarted() { return started_; }
 
+  // --- NEW API ---
+  // TODO(ajwong): This API is incorrect in the face of a streaming decode
+  // protocol like VP8.  However, it breaks the layering abstraction by
+  // depending on the network packet protocol buffer type. I'm going to go
+  // forward with it as is, and then refactor again to support streaming
+  // decodes.
+
+  // Initializes the decoder to draw into the given |frame|.  The |clip|
+  // specifies the region to draw into.  The clip region must fit inside
+  // the dimensions of frame. Failure to do so will CHECK Fail.
+  virtual void Initialize(scoped_refptr<media::VideoFrame> frame,
+                          const gfx::Rect& clip) {}
+
+  // Reset the decoder to an uninitialized state. Release all references to
+  // the initialized |frame|.  Initialize() must be called before the decoder
+  // is used again.
+  virtual void Reset() {}
+
+  // Feeds more data into the decoder.
+  virtual void DecodeBytes(const std::string& encoded_bytes) {}
+
+  // Returns true if decoder is ready to accept data via ProcessRectangleData.
+  virtual bool IsReadyForData() { return false; }
+
  protected:
   // Every decoder will have two internal states because there are three
   // kinds of messages send to PartialDecode().
   //
   // Here's a state diagram:
   //
   //                UpdateStreamBeginRect       UpdateStreamRectData
   //                    ..............              ............
   //                   .              .            .            .
   //                  .                v          .              .
@@ skipping 18 matching lines @@
   // The encoding that this decoder supports.
   UpdateStreamEncoding encoding_;
 
   // Has the decoder been started? I.e., has BeginDecode() been called.
   bool started_;
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_BASE_DECODER_H_