Merge third_party/ots from https://chromium.googlesource.com/external/ots.git at 6e9099c9e28a9dc7b4083f4f9cbcbaef6a8e0031

This commit was generated by merge_from_chromium.py.

Change-Id: I41f3cff0bc39a10029cf02bfed2a13175e52ceae