BUG=401296

The addition of layout qualifier handling in es3 development inadvertently
broke handling of nameless structs.

Change-Id: I805bab7a981d1f7f6227ae043720296fc3454662
Reviewed-on: https://chromium-review.googlesource.com/211860Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Tested-by: Shannon Woods <shannonwoods@chromium.org>