Relanding this as the previous attempt failed due to build errors.

webkit/glue/multipart_response_delegate.h

 // Copyright (c) 2011 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 47 matching lines @@
 namespace WebKit {
 class WebURLLoader;
 class WebURLLoaderClient;
 }
 
 namespace webkit_glue {
 
 // Used by unit tests to access private members.
 class MultipartResponseDelegateTester;
 
-class WEBKIT_GLUE_EXPORT MultipartResponseDelegate {
+class MultipartResponseDelegate {
  public:
   MultipartResponseDelegate(WebKit::WebURLLoaderClient* client,
                             WebKit::WebURLLoader* loader,
                             const WebKit::WebURLResponse& response,
                             const std::string& boundary);
 
   // Passed through from ResourceHandleInternal
   void OnReceivedData(const char* data, int data_len, int encoded_data_length);
   void OnCompletedRequest();
 
@@ skipping 65 matching lines @@
 
   // 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