RLS: Deparameterize core/{dom,editing,clipboard,loader} unit tests.

Bug: 823365
Change-Id: I34bd09b180ed8c7403217d0931cf2e765dc951d8
Reviewed-on: https://chromium-review.googlesource.com/1062288
Reviewed-by: Philip Rogers <pdr@chromium.org>
Commit-Queue: Steve Kobes <skobes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#559205}
4 files changed