Remove HTTP/0.9 support from HttpStreamParser.

net/http/http_stream_parser.cc

Index: net/http/http_stream_parser.cc
diff --git a/net/http/http_stream_parser.cc b/net/http/http_stream_parser.cc
index b673689ed296c510ab1a7d89f764c5424235e5c9..bb0f1f218acc5ba5a34c84772b3b906ce24e4dcf 100644
--- a/net/http/http_stream_parser.cc
+++ b/net/http/http_stream_parser.cc
@@ -832,9 +832,12 @@ int HttpStreamParser::HandleReadHeaderResult(int result) {
       end_offset = read_buf_->offset();
       RecordHeaderParserEvent(HEADER_ALLOWED_TRUNCATED_HEADERS);
     } else {
-      // The response is apparently using HTTP/0.9.  Treat the entire response
-      // as the body.
+      // The server is apparently returning a very short HTTP/0.9 response.
+      // TODO(mmenke): Clean up remnants of HTTP/0.9 code once HTTP/0.9 removal
+      // successfully ships.
       end_offset = 0;
+      // Treat it as an error.
+      return ERR_INVALID_HTTP_RESPONSE;
     }
     int rv = ParseResponseHeaders(end_offset);
     if (rv < 0)
@@ -932,6 +935,8 @@ int HttpStreamParser::FindAndParseResponseHeaders() {
     // Enough data to decide that this is an HTTP/0.9 response.
     // 8 bytes = (4 bytes of junk) + "http".length()
     end_offset = 0;
+    // Treat a an error.
+    return ERR_INVALID_HTTP_RESPONSE;
   }
 
   if (end_offset == -1)