Simplify the user agent code some more since after r255534 it's not affected by the site's URL.

chrome/browser/net/chrome_http_user_agent_settings.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_HTTP_USER_AGENT_SETTINGS_H_
 #define CHROME_BROWSER_NET_CHROME_HTTP_USER_AGENT_SETTINGS_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/prefs/pref_member.h"
 #include "net/url_request/http_user_agent_settings.h"
 
 class PrefService;
 
 // An implementation of |HttpUserAgentSettings| that provides HTTP header
-// Accept-Language value that tracks Pref settings and uses
-// |content::GetUserAgent| to provide the HTTP User-Agent header value.
+// Accept-Language value that tracks Pref settings.
 class ChromeHttpUserAgentSettings : public net::HttpUserAgentSettings {
  public:
   // Must be called on the UI thread.
   explicit ChromeHttpUserAgentSettings(PrefService* prefs);
   // Must be called on the IO thread.
   virtual ~ChromeHttpUserAgentSettings();
 
   void CleanupOnUIThread();
 
   // net::HttpUserAgentSettings implementation
   virtual std::string GetAcceptLanguage() const OVERRIDE;
-  virtual std::string GetUserAgent(const GURL& url) const OVERRIDE;
+  virtual std::string GetUserAgent() const OVERRIDE;
 
  private:
   StringPrefMember pref_accept_language_;
 
   // Avoid re-processing by caching the last value from the preferences and the
   // last result of processing via net::HttpUtil::GenerateAccept*Header().
   mutable std::string last_pref_accept_language_;
   mutable std::string last_http_accept_language_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeHttpUserAgentSettings);
 };
 
 #endif  // CHROME_BROWSER_NET_CHROME_HTTP_USER_AGENT_SETTINGS_H_