The specs for both WebBlueTooth & WebUSB only require a user
activation during a requestDevice call.  So consuming the activation
(vs just checking) is not a strong requirement.  There was a concern
that "not consuming" could possibly mean multiple choosers for a single
user activation but our browser code already handles the situation
gracefully.  Multiple requests to browser is possible from different
tabs anyway, even with (isolated) consumptions in individual tabs.

Therefore it makes sense to remove the consumption behavior here,
which is not spec-ed anyway.  This would fit our goal of a simple
user activation model ("UserActivationV2" project) which should be
simple enough for cross-browser implementation and for a complete spec.

Bug: 786407
Change-Id: I3c9dbf43df34d4cb4a2a33214a6c44847fa7435b
Reviewed-on: https://chromium-review.googlesource.com/775866
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Reviewed-by: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Commit-Queue: Mustaq Ahmed <mustaq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548768}