Move content deduplication into the scan process.

ui/file_manager/file_manager/background/js/duplicate_finder_unittest.html

Index: ui/file_manager/file_manager/background/js/duplicate_finder_unittest.html
diff --git a/ui/file_manager/file_manager/background/js/duplicate_finder_unittest.html b/ui/file_manager/file_manager/background/js/duplicate_finder_unittest.html
index 8ebf1e9c54e6b5f9de4a0b8203470ca687af773a..e14d9520da24c071a2590dd5664c25863c191f27 100644
--- a/ui/file_manager/file_manager/background/js/duplicate_finder_unittest.html
+++ b/ui/file_manager/file_manager/background/js/duplicate_finder_unittest.html
@@ -14,12 +14,14 @@
 
   <script src="../../common/js/async_util.js"></script>
   <script src="../../common/js/mock_entry.js"></script>
+  <script src="../../common/js/test_tracker.js"></script>
   <script src="../../common/js/unittest_util.js"></script>
   <script src="../../common/js/util.js"></script>
   <script src="../../common/js/volume_manager_common.js"></script>
   <script src="../../common/js/importer_common.js"></script>
   <script src="../../common/js/progress_center_common.js"></script>
 
+  <script src="test_import_history.js"></script>
   <script src="mock_volume_manager.js"></script>
   <script src="duplicate_finder.js"></script>
   <script src="volume_manager.js"></script>