[Sync] Start up immediately when entering the sync setup UI.

components/sync_driver/startup_controller.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/sync_driver/startup_controller.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/location.h"
@@ skipping 60 matching lines @@
 
 void StartupController::Reset(const syncer::ModelTypeSet registered_types) {
   received_start_request_ = false;
   start_up_time_ = base::Time();
   start_backend_time_ = base::Time();
   // Don't let previous timers affect us post-reset.
   weak_factory_.InvalidateWeakPtrs();
   registered_types_ = registered_types;
 }
 
-void StartupController::set_setup_in_progress(bool in_progress) {
-  setup_in_progress_ = in_progress;
+void StartupController::SetSetupInProgress(bool setup_in_progress) {
+  setup_in_progress_ = setup_in_progress;
+  if (setup_in_progress_) {
+    TryStart();
+  }
 }
 
 bool StartupController::StartUp(StartUpDeferredOption deferred_option) {
   const bool first_start = start_up_time_.is_null();
   if (first_start)
     start_up_time_ = base::Time::Now();
 
   if (deferred_option == STARTUP_BACKEND_DEFERRED &&
       !base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kSyncDisableDeferredStartup) &&
@@ skipping 118 matching lines @@
                               syncer::MODEL_TYPE_COUNT);
     UMA_HISTOGRAM_ENUMERATION("Sync.Startup.DeferredInitTrigger",
                               TRIGGER_DATA_TYPE_REQUEST,
                               MAX_TRIGGER_VALUE);
   }
   received_start_request_ = true;
   TryStart();
 }
 
 }  // namespace browser_sync