This fixes a crash when run with asserts on ARM GPU:

[2089630:1566159375:0531/202059.262200:ERROR:angle_platform_impl.cc(47)] GetVendorString(133):  ! Assert failed in GetVendorString (../../third_party/angle/src/libANGLE/renderer/driver_utils.cpp:133): vendorId == 0xba5eba11

Bug: angleproject:3492

Change-Id: I786edc459b1567a3eee0034a0d8ae7050ac31952
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1642331
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>