Factor out chunk encoding logic into HttpStreamParser::EncodeChunk().

net/http/http_stream_parser.h

Index: net/http/http_stream_parser.h
diff --git a/net/http/http_stream_parser.h b/net/http/http_stream_parser.h
index ae9fc3e3ed5cfcb151ec3525a4b6da2b5a367298..ee39b83e11c35303ecf81956dfc8e7b34a5c3da2 100644
--- a/net/http/http_stream_parser.h
+++ b/net/http/http_stream_parser.h
@@ -9,6 +9,7 @@
 #include <string>
 
 #include "base/basictypes.h"
+#include "base/string_piece.h"
 #include "net/base/completion_callback.h"
 #include "net/base/net_log.h"
 #include "net/base/upload_data_stream.h"
@@ -77,6 +78,20 @@ class HttpStreamParser  : public ChunkCallback {
   // ChunkCallback methods.
   virtual void OnChunkAvailable() OVERRIDE;
 
+  // Encodes the given |payload| in the chunked format to |output|.
+  // Returns the number of bytes written to |output|. |output_size| should
+  // be large enough to store the encoded chunk, which is payload.size() +
+  // kChunkHeaderFooterSize. Returns -1 if |output_size| is not large

[wtc, 2012/01/18 22:49:24]

Instead of -1, you can return a network error code such as
ERR_FAILED or some other more specific error code.  (We can
add an error code for an output buffer that's not large enough.)

[satorux1, 2012/01/18 23:42:30]

Good idea. I chose to use ERR_FAILED.

[satorux1, 2012/01/18 23:44:02]

Changed it to ERR_INVALID_ARGUMENT as it sounded a bit more appropriate here.

+  // enough.
+  //
+  // The output will look like: "HEX\r\n[payload]\r\n".

[wtc, 2012/01/18 22:49:24]

Nit: should explain what HEX is.  For example,
  where HEX is a length in hexdecimal (without the "0x" prefix)

[satorux1, 2012/01/18 23:42:30]

Good idea. Done.

+  static int EncodeChunk(const base::StringPiece& payload,
+                         char* output,
+                         size_t output_size);
+
+  // The number of extra bytes required to encode a chunk.
+  static const int kChunkHeaderFooterSize;

[wtc, 2012/01/18 22:49:24]

This constant should have the type size_t.

[satorux1, 2012/01/18 23:42:30]

Done.

+
  private:
   // FOO_COMPLETE states implement the second half of potentially asynchronous
   // operations and don't necessarily mean that FOO is complete.