Fix code paths that a layout information is not cleaned correctly.
Fix code paths that a layout information is not cleaned correctly.

- HarfBuzz buffer needs to be cleaned up in all code paths.

bug: b/30229837
Change-Id: Ia0a14b1d0b2511d3a56267313c82ce09a4049486
Tested: on OSX.

google/flatui,google/flatui,google/flatui,google/flatui