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

Index: chrome/browser/net/chrome_http_user_agent_settings.h
===================================================================
--- chrome/browser/net/chrome_http_user_agent_settings.h	(revision 255867)
+++ chrome/browser/net/chrome_http_user_agent_settings.h	(working copy)
@@ -15,8 +15,7 @@
 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.
@@ -28,7 +27,7 @@
 
   // 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_;