Roll src/third_party/dawn 49aae0f3bde2..c0b8132f5547 (5 commits)

This patch also updates the WebGPU implementation in Chrome to match
Dawn API changes.

https://dawn.googlesource.com/dawn.git/+log/49aae0f3bde2..c0b8132f5547

git log 49aae0f3bde2..c0b8132f5547 --date=short --no-merges --format='%ad %ae %s'
2019-07-19 yunchao.he@intel.com Implement RenderPassEncoder::SetViewport: impl on backends
2019-07-19 senorblanco@chromium.org Add some missing #includes.
2019-07-19 cwallez@chromium.org dawn.json: Removed unused "face" bitmask
2019-07-19 enga@chromium.org Add wire tests and mocks for the MemoryTransferService
2019-07-19 enga@chromium.org Add MemoryTransfer interfaces to the wire

Created with:
  gclient setdep -r src/third_party/dawn@c0b8132f5547

The AutoRoll server is located here: https://autoroll.skia.org/r/dawn-chromium-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=luci.chromium.try:dawn-linux-x64-deps-rel;luci.chromium.try:dawn-mac-x64-deps-rel;luci.chromium.try:dawn-win10-x64-deps-rel;luci.chromium.try:dawn-win10-x86-deps-rel
TBR=cwallez@chromium.org

Change-Id: Id71009e931970ab92ce65746db2c7af69e39719c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1711009
Reviewed-by: Austin Eng <enga@chromium.org>
Commit-Queue: Austin Eng <enga@chromium.org>
Cr-Commit-Position: refs/heads/master@{#679553}