Make original_response_headers parameter of NetworkDelegate::OnHeadersReceived const

chrome/browser/net/chrome_network_delegate.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 CHROME_BROWSER_NET_CHROME_NETWORK_DELEGATE_H_
 #define CHROME_BROWSER_NET_CHROME_NETWORK_DELEGATE_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
@@ skipping 65 matching lines @@
                                  const net::CompletionCallback& callback,
                                  GURL* new_url) OVERRIDE;
   virtual int OnBeforeSendHeaders(net::URLRequest* request,
                                   const net::CompletionCallback& callback,
                                   net::HttpRequestHeaders* headers) OVERRIDE;
   virtual void OnSendHeaders(net::URLRequest* request,
                              const net::HttpRequestHeaders& headers) OVERRIDE;
   virtual int OnHeadersReceived(
       net::URLRequest* request,
       const net::CompletionCallback& callback,
-      net::HttpResponseHeaders* original_response_headers,
+      const net::HttpResponseHeaders* original_response_headers,
       scoped_refptr<net::HttpResponseHeaders>* override_response_headers)
       OVERRIDE;
   virtual void OnBeforeRedirect(net::URLRequest* request,
                                 const GURL& new_location) OVERRIDE;
   virtual void OnResponseStarted(net::URLRequest* request) OVERRIDE;
   virtual void OnRawBytesRead(const net::URLRequest& request,
                               int bytes_read) OVERRIDE;
   virtual void OnCompleted(net::URLRequest* request, bool started) OVERRIDE;
   virtual void OnURLRequestDestroyed(net::URLRequest* request) OVERRIDE;
   virtual void OnPACScriptError(int line_number,
@@ skipping 46 matching lines @@
   // static anyway since it is based on a command-line flag.
   static bool g_never_throttle_requests_;
 
   // Pointer to IOThread global, should outlive ChromeNetworkDelegate.
   chrome_browser_net::LoadTimeStats* load_time_stats_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeNetworkDelegate);
 };
 
 #endif  // CHROME_BROWSER_NET_CHROME_NETWORK_DELEGATE_H_