Remove usage of ScopedTaskScheduler from subkey_requester_unittest.cc.

ScopedTaskScheduler is deprecated.

Bug: 708584
Change-Id: I84df1bdec3cd336bd2e9c9366aea032c7809f597
Reviewed-on: https://chromium-review.googlesource.com/586988
Commit-Queue: Mathieu Perreault <mathp@chromium.org>
Reviewed-by: Mathieu Perreault <mathp@chromium.org>
Cr-Commit-Position: refs/heads/master@{#489685}
1 file changed