Roll src/third_party/angle/ 49cef9a52..ad4f9642a (3 commits)

https://chromium.googlesource.com/angle/angle.git/+log/49cef9a52181..ad4f9642a655

$ git log 49cef9a52..ad4f9642a --date=short --no-merges --format='%ad %ae %s'
2018-02-08 ynovikov Allow ANGLE libs to have arbitrary suffix.
2018-03-22 lucferron Vulkan: Depth / stencil attachments bug fixes
2018-03-23 oetuaho Increment ANGLE_SH_VERSION

Created with:
  roll-dep src/third_party/angle


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=luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
TBR=jmadill@chromium.org

Change-Id: I14c42f835b942abbdea348eb66cea440d34a6098
Reviewed-on: https://chromium-review.googlesource.com/978885
Commit-Queue: angle-chromium-autoroll <angle-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Reviewed-by: angle-chromium-autoroll <angle-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#545628}

DEPS

@@ -91,7 +91,7 @@ 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': '49cef9a5218143d4d34d5c5efd159f870eea4ef6',
+  'angle_revision': 'ad4f9642a655bd24205ef156b9fa511ee34f87fd',
   # 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.