Improve UMA tests; improve no-op reconcilor; new reconcilor test.

components/signin/core/browser/account_reconcilor.h

Index: components/signin/core/browser/account_reconcilor.h
diff --git a/components/signin/core/browser/account_reconcilor.h b/components/signin/core/browser/account_reconcilor.h
index 69a2fc75a12c5083abda048e5ee602737caa1d55..9a95dd3c802d0327ff7a11fecd49c1c15f33d395 100644
--- a/components/signin/core/browser/account_reconcilor.h
+++ b/components/signin/core/browser/account_reconcilor.h
@@ -116,6 +116,8 @@ class AccountReconcilor : public KeyedService,
   FRIEND_TEST_ALL_PREFIXES(AccountReconcilorTest, StartReconcileNoopWithDots);
   FRIEND_TEST_ALL_PREFIXES(AccountReconcilorTest, StartReconcileNoopMultiple);
   FRIEND_TEST_ALL_PREFIXES(AccountReconcilorTest, StartReconcileAddToCookie);
+  FRIEND_TEST_ALL_PREFIXES(AccountReconcilorTest,
+                           StartReconcileAddToCookieTwice);
   FRIEND_TEST_ALL_PREFIXES(AccountReconcilorTest, StartReconcileAddToChrome);
   FRIEND_TEST_ALL_PREFIXES(AccountReconcilorTest, StartReconcileBadPrimary);
   FRIEND_TEST_ALL_PREFIXES(AccountReconcilorTest, StartReconcileOnlyOnce);
@@ -167,6 +169,10 @@ class AccountReconcilor : public KeyedService,
       const GoogleServiceAuthError& error,
       const std::vector<std::pair<std::string, bool> >& accounts);
   void ValidateAccountsFromTokenService();
+  // Note internally that this |account_id| is added to the cookie jar.
+  void MarkAccountAsAddedToCookie(const std::string& account_id);
+  // Note internally that this |account_id| is added to the token service.
+  void MarkAccountAsAddedToChrome(const std::string& account_id);
 
   void OnCookieChanged(const net::CanonicalCookie* cookie);