Remove the url parameter from blink::Platform::userAgent since it's not used anymore.

Source/web/FrameLoaderClientImpl.cpp

 /*
  * Copyright (C) 2009, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2011 Apple 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.
@@ skipping 575 matching lines @@
         m_webFrame->client()->didCreateDataSource(m_webFrame, ds.get());
     return ds.release();
 }
 
 String FrameLoaderClientImpl::userAgent(const KURL& url)
 {
     WebString override = m_webFrame->client()->userAgentOverride(m_webFrame, WebURL(url));
     if (!override.isEmpty())
         return override;
 
-    return blink::Platform::current()->userAgent(url);
+    return blink::Platform::current()->userAgent();
 }
 
 String FrameLoaderClientImpl::doNotTrackValue()
 {
     WebString doNotTrack = m_webFrame->client()->doNotTrackValue(m_webFrame);
     if (!doNotTrack.isEmpty())
         return doNotTrack;
     return String();
 }
 
@@ skipping 194 matching lines @@
     return adoptPtr(m_webFrame->client()->createApplicationCacheHost(m_webFrame, client));
 }
 
 void FrameLoaderClientImpl::didStopAllLoaders()
 {
     if (m_webFrame->client())
         m_webFrame->client()->didAbortLoading(m_webFrame);
 }
 
 } // namespace blink