Add Http2FrameDecoderAdapter.

net/spdy/spdy_framer_decoder_adapter.h

 // Copyright (c) 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 NET_SPDY_SPDY_FRAMER_DECODER_ADAPTER_H_
 #define NET_SPDY_SPDY_FRAMER_DECODER_ADAPTER_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 36 matching lines @@
   // Sets whether or not ProcessInput returns after finishing a frame, or
   // continues processing additional frames. Normally ProcessInput processes
   // all input, but this method enables the caller (and visitor) to work with
   // a single frame at a time (or that portion of the frame which is provided
   // as input). Reset() does not change the value of this flag.
   virtual void set_process_single_input_frame(bool v);
   bool process_single_input_frame() const {
     return process_single_input_frame_;
   }
 
-  // Decode the |len| bytes of encoded HTTP/2 starting at |*data|. Returns the
-  // number of bytes consumed. It is safe to pass more bytes in than may be
-  // consumed.
+  // Decode the |len| bytes of encoded HTTP/2 starting at |*data|. Returns
+  // the number of bytes consumed. It is safe to pass more bytes in than
+  // may be consumed. Should process (or otherwise buffer) as much as
+  // available, unless process_single_input_frame is true.
   virtual size_t ProcessInput(const char* data, size_t len) = 0;
 
   // Reset the decoder (used just for tests at this time).
   virtual void Reset() = 0;
 
   // Current state of the decoder.
   virtual SpdyFramer::SpdyState state() const = 0;
 
   // Current error code (NO_ERROR if state != ERROR).
   virtual SpdyFramer::SpdyError error_code() const = 0;
 
-  // Did the most recently decoded frame header appear to be the start of an
-  // HTTP/1.1 (or earlier) response? Used to detect if a backend/server that
-  // we sent a request to, responded with an HTTP/1.1 response?
+  // Has any frame header looked like the start of an HTTP/1.1 (or earlier)
+  // response? Used to detect if a backend/server that we sent a request to
+  // has responded with an HTTP/1.1 (or earlier) response.
   virtual bool probable_http_response() const = 0;
 
  private:
   SpdyFramerVisitorInterface* visitor_ = nullptr;
   SpdyFramerDebugVisitorInterface* debug_visitor_ = nullptr;
   bool process_single_input_frame_ = false;
 };
 
 // Create an instance of NestedSpdyFramerDecoder, which implements
 // SpdyFramerDecoderAdapter, delegating to a SpdyFramer instance that will
@@ skipping 68 matching lines @@
   SpdyFramer* framer() const { return framer_; }
 
  private:
   SpdyFramerVisitorInterface* const visitor_;
   SpdyFramer* const framer_;
 };
 
 }  // namespace net
 
 #endif  // NET_SPDY_SPDY_FRAMER_DECODER_ADAPTER_H_