Merge third_party/angle_dx11 from https://chromium.googlesource.com/external/angle.git at 6d3511e0dfa9160bb70988bf5e3c03f5edecce19

This commit was generated by merge_from_chromium.py.

Change-Id: Ie53adfb92967f5a8a6449076eb0d72f30cf06145