Merge third_party/angle_dx11 from https://chromium.googlesource.com/external/angle.git at 9c318342233f68b915d39c8f1f181b9ef545c4db

This commit was generated by merge_from_chromium.py.

Change-Id: I362f70d6dcdf0f8446efef9b0d27f8db770433d5