Expose ReconcilorState. Rename MergeSession in Signin Tracker.

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 8dbe06c1fd1e971db30fa0f4f69d6138a5508126..35ec8c1e93c7e504d05280f6d0359632e9817b75 100644
--- a/components/signin/core/browser/account_reconcilor.h
+++ b/components/signin/core/browser/account_reconcilor.h
@@ -40,6 +40,13 @@ class AccountReconcilor : public KeyedService,
                           public OAuth2TokenService::Observer,
                           public SigninManagerBase::Observer {
  public:
+  enum State {
+      NOT_RECONCILING,
+      NOT_RECONCILING_ERROR_OCCURED,
+      GATHERING_INFORMATION,
+      APPLYING_CHANGES
+  };
+
   AccountReconcilor(ProfileOAuth2TokenService* token_service,
                     SigninManagerBase* signin_manager,
                     SigninClient* client,
@@ -56,6 +63,9 @@ class AccountReconcilor : public KeyedService,
   // KeyedService implementation.
   void Shutdown() override;
 
+  // Determine what the reconcilor is currently doing.
+  State GetState();
+
  private:
   bool IsRegisteredWithTokenService() const {
     return registered_with_token_service_;
@@ -174,6 +184,9 @@ class AccountReconcilor : public KeyedService,
   // True iff this is the first time the reconcilor is executing.
   bool first_execution_;
 
+  // True iff an error occured during the last attempt to reconcile.
+  bool error_during_last_reconcile_;
+
   // Used during reconcile action.
   // These members are used to validate the gaia cookie.  |gaia_accounts_|
   // holds the state of google accounts in the gaia cookie.  Each element is