[SyncFS] Show if a tracker is demoted or not in chrome://syncfs-internals

chrome/browser/sync_file_system/drive_backend/metadata_database_index_unittest.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 "chrome/browser/sync_file_system/drive_backend/metadata_database_index.h"
 
 #include "chrome/browser/sync_file_system/drive_backend/drive_backend_constants.h"
 #include "chrome/browser/sync_file_system/drive_backend/drive_backend_test_util.h"
 #include "chrome/browser/sync_file_system/drive_backend/leveldb_wrapper.h"
 #include "chrome/browser/sync_file_system/drive_backend/metadata_database.h"
@@ skipping 115 matching lines @@
   EXPECT_TRUE(trackers.has_active());
   EXPECT_EQ(kFileTrackerID, trackers.active_tracker());
 
   EXPECT_TRUE(index()->PickMultiTrackerFileID().empty());
   EXPECT_EQ(kInvalidTrackerID,
             index()->PickMultiBackingFilePath().parent_id);
   EXPECT_EQ(kPlaceholderTrackerID, index()->PickDirtyTracker());
 }
 
 TEST_F(MetadataDatabaseIndexTest, UpdateTest) {
+  EXPECT_FALSE(index()->IsDemotedDirtyTracker(kPlaceholderTrackerID));
   index()->DemoteDirtyTracker(kPlaceholderTrackerID);
+  EXPECT_TRUE(index()->IsDemotedDirtyTracker(kPlaceholderTrackerID));
   EXPECT_EQ(kInvalidTrackerID, index()->PickDirtyTracker());
   index()->PromoteDemotedDirtyTrackers();
   EXPECT_EQ(kPlaceholderTrackerID, index()->PickDirtyTracker());
 
   FileMetadata metadata;
   ASSERT_TRUE(index()->GetFileMetadata("file_id", &metadata));
   FileTracker app_root_tracker;
   ASSERT_TRUE(index()->GetFileTracker(kAppRootTrackerID, &app_root_tracker));
 
   int64 new_tracker_id = 100;
   scoped_ptr<FileTracker> new_tracker =
       test_util::CreateTracker(metadata, new_tracker_id, &app_root_tracker);
   new_tracker->set_active(false);
   index()->StoreFileTracker(new_tracker.Pass());
 
   EXPECT_EQ("file_id", index()->PickMultiTrackerFileID());
   EXPECT_EQ(ParentIDAndTitle(kAppRootTrackerID, std::string("file")),
             index()->PickMultiBackingFilePath());
 
   index()->RemoveFileMetadata("file_id");
   index()->RemoveFileTracker(kFileTrackerID);
 
   EXPECT_FALSE(index()->GetFileMetadata("file_id", nullptr));
   EXPECT_FALSE(index()->GetFileTracker(kFileTrackerID, nullptr));
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system