Roll src/third_party/angle/ a98a28112..9db70de8e (2 commits)

https://chromium.googlesource.com/angle/angle.git/+log/a98a28112b0e..9db70de8ecb6

$ git log a98a28112..9db70de8e --date=short --no-merges --format='%ad %ae %s'
2017-07-04 cwallez Reland: Implement EGL_ANGLE_iosurface_client_buffer
2017-12-12 cwallez Add test for Chromium's EGL_D3D_TEXTURE pbuffer creation

Created with:
  roll-dep src/third_party/angleBUG=794086


The AutoRoll server is located here: https://angle-chromium-roll.skia.org

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=master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
TBR=cwallez@chromium.org

Change-Id: I2c715d83485f7eccf3873d327bf956ce0bb51559
Reviewed-on: https://chromium-review.googlesource.com/823528Reviewed-by: angle-deps-roller . <angle-deps-roller@chromium.org>
Commit-Queue: angle-deps-roller . <angle-deps-roller@chromium.org>
Cr-Commit-Position: refs/heads/master@{#523720}

DEPS

@@ -86,7 +86,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling ANGLE
   # and whatever else without interference from each other.
-  'angle_revision': 'a98a28112b0e915a511af9956ab92b3143338313',
+  'angle_revision': '9db70de8ecb6bf744c759fc8cd25b1cde717142c',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling build tools
   # and whatever else without interference from each other.