Correct data size argument type in resource loading path to unsigned

Source/core/loader/appcache/ApplicationCacheHost.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 114 matching lines @@
 }
 
 void ApplicationCacheHost::didReceiveResponseForMainResource(const ResourceResponse& response)
 {
     if (m_host) {
         WrappedResourceResponse wrapped(response);
         m_host->didReceiveResponseForMainResource(wrapped);
     }
 }
 
-void ApplicationCacheHost::mainResourceDataReceived(const char* data, int length)
+void ApplicationCacheHost::mainResourceDataReceived(const char* data, unsigned length)
 {
     if (m_host)
         m_host->didReceiveDataForMainResource(data, length);
 }
 
 void ApplicationCacheHost::failedLoadingMainResource()
 {
     if (m_host)
         m_host->didFinishLoadingMainResource(false);
 }
@@ skipping 143 matching lines @@
 {
     notifyApplicationCache(ERROR_EVENT, 0, 0, reason, url.string(), status, message);
 }
 
 void ApplicationCacheHost::trace(Visitor* visitor)
 {
     visitor->trace(m_domApplicationCache);
 }
 
 } // namespace blink