SyncFS: Add ConflictResolverTest

BUG=240165
TEST=unit_tests --gtest_filter=ConflictResolverTest.*
NOTRY=true

Review URL: https://codereview.chromium.org/98053002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238307 0039d316-1c4b-4281-b951-d872f2087c98

chrome/chrome_tests_unit.gypi

@@ -1364,6 +1364,7 @@
         'browser/sync/test/test_http_bridge_factory.h',
         'browser/sync/test_profile_sync_service.cc',
         'browser/sync/test_profile_sync_service.h',
+        'browser/sync_file_system/drive_backend/conflict_resolver_unittest.cc',
         'browser/sync_file_system/drive_backend/drive_backend_test_util.cc',
         'browser/sync_file_system/drive_backend/drive_backend_test_util.h',
         'browser/sync_file_system/drive_backend/list_changes_task_unittest.cc',