Add WebSocketError to indicate decoding failure reason

net/websockets/websocket_frame_parser.cc

Index: net/websockets/websocket_frame_parser.cc
diff --git a/net/websockets/websocket_frame_parser.cc b/net/websockets/websocket_frame_parser.cc
index edbd0e6fc82bf3baaa88662372474e1929cb107c..8053a138e84e669537d56d02c6df2281208d7009 100644
--- a/net/websockets/websocket_frame_parser.cc
+++ b/net/websockets/websocket_frame_parser.cc
@@ -36,7 +36,8 @@ namespace net {
 WebSocketFrameParser::WebSocketFrameParser()
     : current_read_pos_(0),
       frame_offset_(0),
-      failed_(false) {
+      failed_(false),
+      error_code_(WS_OK) {
   std::fill(masking_key_,
             masking_key_ + WebSocketFrameHeader::kMaskingKeyLength,
             '\0');
@@ -121,8 +122,6 @@ void WebSocketFrameParser::DecodeFrameHeader() {
 
   bool masked = (second_byte & kMaskBit) != 0;
   uint64 payload_length = second_byte & kPayloadLengthMask;
-  bool valid_length_format = true;
-  bool message_too_big = false;
   if (payload_length == kPayloadLengthWithTwoByteExtendedLengthField) {
     if (end - current < 2)
       return;
@@ -131,20 +130,19 @@ void WebSocketFrameParser::DecodeFrameHeader() {
     current += 2;
     payload_length = payload_length_16;
     if (payload_length <= kMaxPayloadLengthWithoutExtendedLengthField)
-      valid_length_format = false;
+      error_code_ = WS_ERR_PROTOCOL_ERROR;
   } else if (payload_length == kPayloadLengthWithEightByteExtendedLengthField) {
     if (end - current < 8)
       return;
     ReadBigEndian(current, &payload_length);
     current += 8;
     if (payload_length <= kuint16max ||
-        payload_length > static_cast<uint64>(kint64max)) {
-      valid_length_format = false;
-    }
-    if (payload_length > static_cast<uint64>(kint32max))
-      message_too_big = true;
+        payload_length > static_cast<uint64>(kint64max))

[mmenke, 2012/08/01 14:44:59]

nit:  Google style (Or maybe Chrome style, can't remember which) is to use
braces when the conditional takes more than one line.

+      error_code_ = WS_ERR_PROTOCOL_ERROR;
+    else if (payload_length > static_cast<uint64>(kint32max))
+      error_code_ = WS_ERR_MESSAGE_TOO_BIG;
   }
-  if (!valid_length_format || message_too_big) {
+  if (error_code_ != WS_OK) {
     failed_ = true;
     buffer_.clear();
     current_read_pos_ = 0;