Make original_response_headers parameter of NetworkDelegate::OnHeadersReceived const

chrome/browser/extensions/api/web_request/web_request_api_helpers.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 "chrome/browser/extensions/api/web_request/web_request_api_helpers.h"
 
 #include <cmath>
 
 #include "base/bind.h"
 #include "base/string_number_conversions.h"
@@ skipping 222 matching lines @@
       }
     }
   }
   return result;
 }
 
 EventResponseDelta* CalculateOnHeadersReceivedDelta(
     const std::string& extension_id,
     const base::Time& extension_install_time,
     bool cancel,
-    net::HttpResponseHeaders* old_response_headers,
+    const net::HttpResponseHeaders* old_response_headers,
     ResponseHeaders* new_response_headers) {
   EventResponseDelta* result =
       new EventResponseDelta(extension_id, extension_install_time);
   result->cancel = cancel;
 
   if (!new_response_headers)
     return result;
 
   // Find deleted headers (header keys are treated case insensitively).
   {
@@ skipping 815 matching lines @@
 void ClearCacheOnNavigation() {
   if (content::BrowserThread::CurrentlyOn(content::BrowserThread::UI)) {
     ClearCacheOnNavigationOnUI();
   } else {
     content::BrowserThread::PostTask(content::BrowserThread::UI, FROM_HERE,
                                      base::Bind(&ClearCacheOnNavigationOnUI));
   }
 }
 
 }  // namespace extension_web_request_api_helpers