Roll src/third_party/dawn/ 61791eae3..2960ec336 (2 commits)

https://dawn.googlesource.com/dawn.git/+log/61791eae36b8..2960ec33667a

$ git log 61791eae3..2960ec336 --date=short --no-merges --format='%ad %ae %s'
2018-11-01 cwallez Add support for all of Chromium's CPU architectures.
2018-11-01 senorblanco D3D12 fix for register binding offsets.

Created with:
  roll-dep src/third_party/dawn
TBR=kainino@chromium.org

BUG=870747

Change-Id: I6942e2e387f367be3aee7f707152375e6d6c0254
Reviewed-on: https://chromium-review.googlesource.com/c/1311932Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Commit-Queue: Kai Ninomiya <kainino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604612}

DEPS

@@ -240,7 +240,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling feed
   # and whatever else without interference from each other.
-  'dawn_revision': '61791eae36b8155219f6217b64b28eb4f54e3396',
+  'dawn_revision': '2960ec33667a11bb4445dfe8154aef133c741afe',
 }
 
 # Only these hosts are allowed for dependencies in this DEPS file.