Revert "Merge pull request #13161 from luke-chang/919370_unit_test_for_pinyin"

This reverts commit 9ab17bf1759b8abd5e1de7e71c98f617a87a7a25, reversing
changes made to 1dd8c7d1209cdf23bd8bdfd1878fcdcdc58fb2bc.
Merge pull request #13220 from lightsofapollo/revert-9ab17bf1759b8abd5e1de7e71c98f617a87a7a25

Revert "Merge pull request #13161 from     luke-chang/919370_unit_test_for_pinyin"