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

webkit/glue/weburlresponse_extradata_impl.h

 // Copyright (c) 2012 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.
 
 #ifndef WEBKIT_GLUE_WEBURLRESPONSE_EXTRADATA_IMPL_H_
 #define WEBKIT_GLUE_WEBURLRESPONSE_EXTRADATA_IMPL_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebURLResponse.h"
-#include "webkit/glue/webkit_glue_export.h"
 
 namespace webkit_glue {
 
 // Base class for Chrome's implementation of the "extra data".
-class WEBKIT_GLUE_EXPORT WebURLResponseExtraDataImpl
-    : NON_EXPORTED_BASE(public WebKit::WebURLResponse::ExtraData) {
+class WebURLResponseExtraDataImpl : public WebKit::WebURLResponse::ExtraData {
  public:
   explicit WebURLResponseExtraDataImpl(
       const std::string& npn_negotiated_protocol);
   virtual ~WebURLResponseExtraDataImpl();
 
   const std::string& npn_negotiated_protocol() const {
     return npn_negotiated_protocol_;
   }
 
   // Flag whether this request was loaded via an explicit proxy
@@ skipping 46 matching lines @@
   bool was_fetched_via_spdy_;
   bool was_npn_negotiated_;
   bool was_alternate_protocol_available_;
 
   DISALLOW_COPY_AND_ASSIGN(WebURLResponseExtraDataImpl);
 };
 
 }  // namespace webkit_glue
 
 #endif  // WEBKIT_GLUE_WEBURLRESPONSE_EXTRADATA_IMPL_H_