Revert of Sync: Support multiple setup UIs.

components/browser_sync/browser/profile_sync_service.cc

Index: components/browser_sync/browser/profile_sync_service.cc
diff --git a/components/browser_sync/browser/profile_sync_service.cc b/components/browser_sync/browser/profile_sync_service.cc
index 5f0c8da7319e3d3b01d721f4aeec014651e682a5..95a951dfedc552f8a56d2297eb16ad4dba80a54d 100644
--- a/components/browser_sync/browser/profile_sync_service.cc
+++ b/components/browser_sync/browser/profile_sync_service.cc
@@ -1528,19 +1528,15 @@
   return !IsFirstSetupComplete() && startup_controller_->IsSetupInProgress();
 }
 
-std::unique_ptr<sync_driver::SyncSetupInProgressHandle>
-ProfileSyncService::GetSetupInProgressHandle() {
-  if (++outstanding_setup_in_progress_handles_ == 1) {
-    DCHECK(!startup_controller_->IsSetupInProgress());
-    startup_controller_->SetSetupInProgress(true);
-
-    NotifyObservers();
-  }
-
-  return std::unique_ptr<sync_driver::SyncSetupInProgressHandle>(
-      new sync_driver::SyncSetupInProgressHandle(
-          base::Bind(&ProfileSyncService::OnSetupInProgressHandleDestroyed,
-                     weak_factory_.GetWeakPtr())));
+void ProfileSyncService::SetSetupInProgress(bool setup_in_progress) {
+  // This method is a no-op if |setup_in_progress_| remains unchanged.
+  if (startup_controller_->IsSetupInProgress() == setup_in_progress)
+    return;
+
+  startup_controller_->SetSetupInProgress(setup_in_progress);
+  if (!setup_in_progress && IsBackendInitialized())
+    ReconfigureDatatypeManager();
+  NotifyObservers();
 }
 
 bool ProfileSyncService::IsSyncAllowed() const {
@@ -2548,18 +2544,3 @@
     const {
   return unrecoverable_error_location_;
 }
-
-void ProfileSyncService::OnSetupInProgressHandleDestroyed() {
-  DCHECK_GT(outstanding_setup_in_progress_handles_, 0);
-
-  // Don't re-start Sync until all outstanding handles are destroyed.
-  if (--outstanding_setup_in_progress_handles_ != 0)
-    return;
-
-  DCHECK(startup_controller_->IsSetupInProgress());
-  startup_controller_->SetSetupInProgress(false);
-
-  if (IsBackendInitialized())
-    ReconfigureDatatypeManager();
-  NotifyObservers();
-}