GitLab

Remove unnecessary includes.
Move a few param definitions over to content_param_traits_macros.h

BUG=1097816

Change-Id: I684d06cb3d518448cbb15049477f4bb3ce65b779
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2490247
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Reviewed-by: Martin Barbella <mbarbella@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821739}