Make original_response_headers parameter of NetworkDelegate::OnHeadersReceived const

net/proxy/proxy_script_fetcher_impl_unittest.cc

 // 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.
 
 #include "net/proxy/proxy_script_fetcher_impl.h"
 
 #include <string>
 
 #include "base/file_path.h"
 #include "base/compiler_specific.h"
@@ skipping 123 matching lines @@
                                   HttpRequestHeaders* headers) OVERRIDE {
     return OK;
   }
 
   virtual void OnSendHeaders(URLRequest* request,
                              const HttpRequestHeaders& headers) OVERRIDE {}
 
   virtual int OnHeadersReceived(
       URLRequest* request,
       const CompletionCallback& callback,
-      HttpResponseHeaders* original_response_headers,
+      const HttpResponseHeaders* original_response_headers,
       scoped_refptr<HttpResponseHeaders>* override_response_headers)
       OVERRIDE {
     return OK;
   }
 
   virtual void OnBeforeRedirect(URLRequest* request,
                                 const GURL& new_location) OVERRIDE {}
 
   virtual void OnResponseStarted(URLRequest* request) OVERRIDE {}
 
@@ skipping 333 matching lines @@
   {
     GURL url(kEncodedUrlBroken);
     string16 text;
     TestCompletionCallback callback;
     int result = pac_fetcher.Fetch(url, &text, callback.callback());
     EXPECT_EQ(ERR_FAILED, result);
   }
 }
 
 }  // namespace net