Avoid having every frame of a multipart response create a

webkit/glue/multipart_response_delegate.h

 // Copyright (c) 2006-2009 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.
 //
 // A delegate class of WebURLLoaderImpl that handles multipart/x-mixed-replace
 // data.  We special case multipart/x-mixed-replace because WebCore expects a
 // separate didReceiveResponse for each new message part.
 //
 // Most of the logic and edge case handling are based on the Mozilla's
 // implementation in netwerk/streamconv/converters/nsMultiMixedConv.cpp.
@@ skipping 112 matching lines @@
   // true until we get our first on received data call
   bool first_received_data_;
 
   // true if we're truncated in the middle of a header
   bool processing_headers_;
 
   // true when we're done sending information.  At that point, we stop
   // processing AddData requests.
   bool stop_sending_;
 
+  // true after we've sent our first response to the WebURLLoaderClient.
+  bool has_sent_first_response_;
+
   DISALLOW_COPY_AND_ASSIGN(MultipartResponseDelegate);
 };
 
 }  // namespace webkit_glue
 
 #endif