RC: Trim some unused includes.

Bug: 910288
Change-Id: I0ab5c1d9f96662d6d5a894a93d8ed031a8655386
Reviewed-on: https://chromium-review.googlesource.com/c/1355320
Reviewed-by: François Doray <fdoray@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Sigurður Ásgeirsson <siggi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612647}
3 files changed