Revert 270308 "sync: Improve handling of bad UniquePositions"

trunk/src/sync/internal_api/public/base/unique_position.h

Index: trunk/src/sync/internal_api/public/base/unique_position.h
===================================================================
--- trunk/src/sync/internal_api/public/base/unique_position.h	(revision 270322)
+++ trunk/src/sync/internal_api/public/base/unique_position.h	(working copy)
@@ -46,10 +46,6 @@
   static bool IsValidSuffix(const std::string& suffix);
   static bool IsValidBytes(const std::string& bytes);
 
-  // Returns a valid, but mostly random suffix.
-  // Avoid using this; it can lead to inconsistent sort orderings if misused.
-  static std::string RandomSuffix();
-
   // Returns an invalid position.
   static UniquePosition CreateInvalid();