Roll third_party/externals/angle2 6446c8882fa3..3115a0fc17fa (2 commits)

https://chromium.googlesource.com/angle/angle.git/+log/6446c8882fa3..3115a0fc17fa


git log 6446c8882fa3..3115a0fc17fa --date=short --no-merges --format='%ad %ae %s'
2019-03-29 ynovikov@chromium.org Sync run_code_generation_hashes.json after glslang autoroll.
2019-03-29 angle-autoroll@skia-public.iam.gserviceaccount.com Roll ./third_party/spirv-tools/src 2ff54e34ed37..fcb845310450 (1 commits)


Created with:
  gclient setdep -r third_party/externals/angle2@3115a0fc17fa

The AutoRoll server is located here: https://autoroll.skia.org/r/angle-skia-autoroll

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff, who should
be CC'd on the roll, and stop the roller if necessary.

CQ_INCLUDE_TRYBOTS=skia.primary:Build-Debian9-Clang-x86_64-Release-ANGLE;skia.primary:Perf-Win10-Clang-AlphaR2-GPU-RadeonR9M470X-x86_64-Debug-All-ANGLE;skia.primary:Perf-Win10-Clang-NUC5i7RYH-GPU-IntelIris6100-x86_64-Debug-All-ANGLE;skia.primary:Perf-Win10-Clang-NUC6i5SYK-GPU-IntelIris540-x86_64-Debug-All-ANGLE;skia.primary:Perf-Win10-Clang-NUCD34010WYKH-GPU-IntelHD4400-x86_64-Debug-All-ANGLE;skia.primary:Perf-Win10-Clang-ShuttleC-GPU-GTX960-x86_64-Debug-All-ANGLE;skia.primary:Test-Win10-Clang-AlphaR2-GPU-RadeonR9M470X-x86_64-Debug-All-ANGLE;skia.primary:Test-Win10-Clang-NUC6i5SYK-GPU-IntelIris540-x86_64-Debug-All-ANGLE;skia.primary:Test-Win10-Clang-NUCD34010WYKH-GPU-IntelHD4400-x86_64-Debug-All-ANGLE;skia.primary:Test-Win10-Clang-ShuttleC-GPU-GTX960-x86_64-Debug-All-ANGLE
TBR=jlavrova@google.com

Change-Id: I02bb42efa5b6d6a179ed40dfd9611696a4d93014
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/205174
Reviewed-by: skia-autoroll <skia-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: skia-autoroll <skia-autoroll@skia-public.iam.gserviceaccount.com>