Revert of Sync: Support multiple setup UIs.

components/browser_sync/browser/profile_sync_service.h

Index: components/browser_sync/browser/profile_sync_service.h
diff --git a/components/browser_sync/browser/profile_sync_service.h b/components/browser_sync/browser/profile_sync_service.h
index 21570498856c9d50b3f80d3146dde40dcaa387c1..3fecc3197fa8b306fb396ec8b051385d7a41aae3 100644
--- a/components/browser_sync/browser/profile_sync_service.h
+++ b/components/browser_sync/browser/profile_sync_service.h
@@ -165,16 +165,14 @@
 //   that control the initial sync download:
 //
 //    * SetFirstSetupComplete()
-//    * GetSetupInProgressHandle()
+//    * SetSetupInProgress()
 //
 //   SetFirstSetupComplete() should be called once the user has finished setting
-//   up sync at least once on their account. GetSetupInProgressHandle() should
-//   be called while the user is actively configuring their account. The handle
-//   should be deleted once configuration is complete.
-//
-//   Once first setup has completed and there are no outstanding
-//   setup-in-progress handles, CanConfigureDataTypes() will return true and
-//   datatype configuration can begin.
+//   up sync at least once on their account. SetSetupInProgress(true) should be
+//   called while the user is actively configuring their account, and then
+//   SetSetupInProgress(false) should be called when configuration is complete.
+//   Once both these conditions have been met, CanConfigureDataTypes() will
+//   return true and datatype configuration can begin.
 class ProfileSyncService : public sync_driver::SyncService,
                            public sync_driver::SyncFrontend,
                            public sync_driver::SyncPrefObserver,
@@ -282,8 +280,7 @@
                             syncer::ModelTypeSet chosen_types) override;
   void SetFirstSetupComplete() override;
   bool IsFirstSetupInProgress() const override;
-  std::unique_ptr<sync_driver::SyncSetupInProgressHandle>
-  GetSetupInProgressHandle() override;
+  void SetSetupInProgress(bool setup_in_progress) override;
   bool IsSetupInProgress() const override;
   bool ConfigurationDone() const override;
   const GoogleServiceAuthError& GetAuthError() const override;
@@ -805,9 +802,6 @@
   // True if setup has been completed at least once and is not in progress.
   bool CanConfigureDataTypes() const;
 
-  // Called when a SetupInProgressHandle issued by this instance is destroyed.
-  virtual void OnSetupInProgressHandleDestroyed();
-
   // This profile's SyncClient, which abstracts away non-Sync dependencies and
   // the Sync API component factory.
   std::unique_ptr<sync_driver::SyncClient> sync_client_;
@@ -849,10 +843,6 @@
   // Indicates if this is the first time sync is being configured.  This value
   // is equal to !IsFirstSetupComplete() at the time of OnBackendInitialized().
   bool is_first_time_sync_configure_;
-
-  // Number of UIs currently configuring the Sync service. When this number
-  // is decremented back to zero, Sync setup is marked no longer in progress.
-  int outstanding_setup_in_progress_handles_ = 0;
 
   // List of available data type controllers.
   sync_driver::DataTypeController::TypeMap data_type_controllers_;