Revert 84197 - Add one-time randomization support for FieldTrial, and the ability to

chrome/browser/metrics/metrics_service.h

Index: chrome/browser/metrics/metrics_service.h
===================================================================
--- chrome/browser/metrics/metrics_service.h	(revision 84367)
+++ chrome/browser/metrics/metrics_service.h	(working copy)
@@ -82,10 +82,6 @@
   void StartRecordingOnly();
   void Stop();
 
-  // Returns the client ID for this client, or the empty string if metrics
-  // recording is not currently running.
-  std::string GetClientId();
-
   // At startup, prefs needs to be called with a list of all the pref names and
   // types we'll be using.
   static void RegisterPrefs(PrefService* local_state);