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

content/public/common/content_client.h

Index: content/public/common/content_client.h
===================================================================
--- content/public/common/content_client.h	(revision 255867)
+++ content/public/common/content_client.h	(working copy)
@@ -65,16 +65,6 @@
 CONTENT_EXPORT ContentUtilityClient* SetUtilityClientForTesting(
     ContentUtilityClient* u);
 
-// Returns the user agent string being used by the browser. SetContentClient()
-// must be called prior to calling this, and this routine must be used
-// instead of webkit_glue::GetUserAgent() in order to ensure that we use
-// the same user agent string everywhere.
-// TODO(dpranke): This is caused by webkit_glue being a library that can
-// get linked into multiple linkable objects, causing us to have multiple
-// static values of the user agent. This will be fixed when we clean up
-// webkit_glue.
-CONTENT_EXPORT const std::string& GetUserAgent(const GURL& url);
-
 // Interface that the embedder implements.
 class CONTENT_EXPORT ContentClient {
  public: