Fixes known issue that specialization doesn't rigorously checked to
verify that specialization signature precisely matches generic
declaration.

Change-Id: I884f7f16a467ab716d2b0c553485f4b1c55ed806
Reviewed-on: https://chromium-review.googlesource.com/1063613Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Daniel Clifford <danno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53252}