Remove @apply

We never released it, and we're abandoning @apply in favour of ::part.
https://bugs.chromium.org/p/chromium/issues/detail?id=637419
http://www.xanthir.com/b4o00
https://www.chromestatus.com/feature/5753701012602880

Change-Id: Ib390a6b9413e4e1be763be4791ef81810a10cec9
Reviewed-on: https://chromium-review.googlesource.com/765634
Commit-Queue: meade_UTC10 <meade@chromium.org>
Reviewed-by: nainar <nainar@chromium.org>
Reviewed-by: Rick Byers <rbyers@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Cr-Commit-Position: refs/heads/master@{#516609}
53 files changed