This is in preparation of removing the using statements that are
currently in third_party/inspector_protocol/lib/Collections_h.template.

Once this is done I can update
https://chromium-review.googlesource.com/c/deps/inspector_protocol/+/1135832
some more and eventually roll it into v8 (and chromium's third party).

R=dgozman

Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I75a7b291715f241e3b58fb97ac91a0b0ff0ca70b
Reviewed-on: https://chromium-review.googlesource.com/1135968
Commit-Queue: Johannes Henkel <johannes@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54422}