Roll skia/third_party/externals/angle2/ 1b7ed0ef2..981f0f8f6 (4 commits)

https://chromium.googlesource.com/angle/angle.git/+log/1b7ed0ef2d23..981f0f8f6a34

$ git log 1b7ed0ef2..981f0f8f6 --date=short --no-merges --format='%ad %ae %s'
2017-09-21 jmadill Add flag to do a fast pass through perf tests.
2017-09-20 jmadill D3D11: Minor optimizations to vertex attribute application.
2017-09-20 jmadill Minor cleanup to setIndexBuffer.
2017-09-20 jmadill Improve the speed of MarkAttachmentsDirty.

Created with:
  roll-dep skia/third_party/externals/angle2
BUG=725308


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

If the roll is causing failures, see:
http://www.chromium.org/developers/tree-sheriffs/sheriff-details-chromium#TOC-Failures-due-to-DEPS-rolls


CQ_INCLUDE_TRYBOTS=skia.primary:Perf-Win10-MSVC-AlphaR2-GPU-RadeonR9M470X-x86_64-Debug-ANGLE,Perf-Win10-MSVC-Golo-GPU-QuadroP400-x86_64-Debug-ANGLE,Perf-Win10-MSVC-NUC5i7RYH-GPU-IntelIris6100-x86_64-Debug-ANGLE,Perf-Win10-MSVC-NUC6i5SYK-GPU-IntelIris540-x86_64-Debug-ANGLE,Perf-Win10-MSVC-NUCD34010WYKH-GPU-IntelHD4400-x86_64-Debug-ANGLE,Perf-Win10-MSVC-ShuttleC-GPU-GTX960-x86_64-Debug-ANGLE,Test-Win10-MSVC-AlphaR2-GPU-RadeonR9M470X-x86_64-Debug-ANGLE,Test-Win10-MSVC-Golo-GPU-QuadroP400-x86_64-Debug-ANGLE,Test-Win10-MSVC-NUC5i7RYH-GPU-IntelIris6100-x86_64-Debug-ANGLE,Test-Win10-MSVC-NUC6i5SYK-GPU-IntelIris540-x86_64-Debug-ANGLE,Test-Win10-MSVC-NUCD34010WYKH-GPU-IntelHD4400-x86_64-Debug-ANGLE,Test-Win10-MSVC-ShuttleC-GPU-GTX960-x86_64-Debug-ANGLE
TBR=fmalita@google.com

Change-Id: I69a0ded10bc43bfd7aaaa01cd9b03cc12c31bfa7
Reviewed-on: https://skia-review.googlesource.com/49820
Reviewed-by: angle-deps-roller . <angle-deps-roller@chromium.org>
Commit-Queue: angle-deps-roller . <angle-deps-roller@chromium.org>
diff --git a/DEPS b/DEPS
index 96a8ddd..3109e60 100644
--- a/DEPS
+++ b/DEPS
@@ -3,7 +3,7 @@
 deps = {
   "buildtools"                          : "https://chromium.googlesource.com/chromium/buildtools.git@e6b510a9daf822bbe9f922c200c58150803d2fd8",
   "common"                              : "https://skia.googlesource.com/common.git@9737551d7a52c3db3262db5856e6bcd62c462b92",
-  "third_party/externals/angle2"        : "https://chromium.googlesource.com/angle/angle.git@1b7ed0ef2d230989bb026ea7c6a1fc3246cc9647",
+  "third_party/externals/angle2"        : "https://chromium.googlesource.com/angle/angle.git@981f0f8f6a34b6144e573692c6fcab1625a5f67c",
   "third_party/externals/dng_sdk"       : "https://android.googlesource.com/platform/external/dng_sdk.git@96443b262250c390b0caefbf3eed8463ba35ecae",
   "third_party/externals/expat"         : "https://android.googlesource.com/platform/external/expat.git@android-6.0.1_r55",
   "third_party/externals/freetype"      : "https://skia.googlesource.com/third_party/freetype2.git@447a0b62634802d8acdb56008cff5ff4e50be244",