[Sync] Make BackendMigrator not wait for full sync cycles

chrome/browser/sync/engine/sync_scheduler_unittest.cc

 // Copyright (c) 2011 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 "base/bind.h"
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_callback_factory.h"
 #include "base/message_loop.h"
 #include "base/task.h"
@@ skipping 991 matching lines @@
   scheduler()->Stop();
   Mock::VerifyAndClearExpectations(syncer());
 
   // Cleanup disabled types.
   EXPECT_CALL(*syncer(),
               SyncShare(_, CLEANUP_DISABLED_TYPES, CLEANUP_DISABLED_TYPES));
   StartSyncScheduler(SyncScheduler::NORMAL_MODE);
   RunLoop();
 
   scheduler()->ScheduleCleanupDisabledTypes();
-  PumpLoop();
+  // Only need to pump once, as ScheduleCleanupDisabledTypes()
+  // schedules the job directly.
   PumpLoop();
 
   scheduler()->Stop();
   Mock::VerifyAndClearExpectations(syncer());
 
   // Poll.
   EXPECT_CALL(*syncer(), SyncShare(_, SYNCER_BEGIN, SYNCER_END))
       .Times(AtLeast(1))
       .WillRepeatedly(QuitLoopNowAction());
   const TimeDelta poll(TimeDelta::FromMilliseconds(10));
@@ skipping 47 matching lines @@
   PumpLoop();
   // Pump again to run job.
   PumpLoop();
 
   scheduler()->Stop();
 
   EXPECT_TRUE(expected == context()->previous_session_routing_info());
 }
 
 }  // namespace browser_sync