Merge third_party/angle_dx11 from https://chromium.googlesource.com/external/angle.git at 3bc1f246ff86182ceb05dc2d7c55f7c2ab44fd46

This commit was generated by merge_from_chromium.py.

Change-Id: I78ff13fbdf53ff3ecb0ab1a9acb29fc042e8562e