Handle birthday errors by disabling sync and deleting sync data.

chrome/test/sync/engine/mock_connection_manager.h

Index: chrome/test/sync/engine/mock_connection_manager.h
===================================================================
--- chrome/test/sync/engine/mock_connection_manager.h	(revision 52107)
+++ chrome/test/sync/engine/mock_connection_manager.h	(working copy)
@@ -158,6 +158,10 @@
     use_legacy_bookmarks_protocol_ = value;
   }
 
+  void set_store_birthday(string new_birthday) {
+    store_birthday_ = new_birthday;
+  }
+
   // Retrieve the number of GetUpdates requests that the mock server has
   // seen since the last time this function was called.  Can be used to
   // verify that a GetUpdates actually did or did not happen after running