[Sync] Make syncer commands avoid posting tasks on threads with no work to do

chrome/browser/sync/engine/syncer_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.
 //
 // Syncer unit tests. Unfortunately a lot of these tests
 // are outdated and need to be reworked and updated.
 
 #include <algorithm>
 #include <limits>
 #include <list>
@@ skipping 2144 matching lines @@
   SyncShareAsDelegate();
   {
     ReadTransaction trans(FROM_HERE, dir);
     Entry entry(&trans, syncable::GET_BY_ID, id);
     ASSERT_TRUE(entry.good());
     EXPECT_TRUE(entry.Get(MTIME) == test_time);
   }
 }
 
 TEST_F(SyncerTest, ParentAndChildBothMatch) {
+  syncable::ModelTypeBitSet all_types;
+  all_types.set();
   ScopedDirLookup dir(syncdb_.manager(), syncdb_.name());
   CHECK(dir.good());
   syncable::Id parent_id = ids_.NewServerId();
   syncable::Id child_id = ids_.NewServerId();
 
   {
     WriteTransaction wtrans(FROM_HERE, UNITTEST, dir);
     MutableEntry parent(&wtrans, CREATE, root_id_, "Folder");
     ASSERT_TRUE(parent.good());
     parent.Put(IS_DIR, true);
@@ skipping 16 matching lines @@
   SyncShareAsDelegate();
   SyncShareAsDelegate();
   {
     ReadTransaction trans(FROM_HERE, dir);
     Directory::ChildHandles children;
     dir->GetChildHandlesById(&trans, root_id_, &children);
     EXPECT_EQ(1u, children.size());
     dir->GetChildHandlesById(&trans, parent_id, &children);
     EXPECT_EQ(1u, children.size());
     Directory::UnappliedUpdateMetaHandles unapplied;
-    dir->GetUnappliedUpdateMetaHandles(&trans, &unapplied);
+    dir->GetUnappliedUpdateMetaHandles(&trans, all_types, &unapplied);
     EXPECT_EQ(0u, unapplied.size());
     syncable::Directory::UnsyncedMetaHandles unsynced;
     dir->GetUnsyncedMetaHandles(&trans, &unsynced);
     EXPECT_EQ(0u, unsynced.size());
     saw_syncer_event_ = false;
   }
 }
 
 TEST_F(SyncerTest, CommittingNewDeleted) {
   ScopedDirLookup dir(syncdb_.manager(), syncdb_.name());
@@ skipping 3143 matching lines @@
   Add(low_id_);
   Add(high_id_);
   SyncShareAsDelegate();
   ExpectLocalOrderIsByServerId();
 }
 
 const SyncerTest::CommitOrderingTest
 SyncerTest::CommitOrderingTest::LAST_COMMIT_ITEM = {-1, TestIdFactory::root()};
 
 }  // namespace browser_sync