Fix header guards in ui/.

Generated mechanically as follows:

git ls-files '*.h' | grep -E '^ui/' | \
    xargs parallel cpplint.py --filter=-,+build/header_guard -- 2>&1 | \
    grep build/header_guard | tools/apply_cpplint_header_guard.py

Bug: 1200694
Change-Id: Ib235f09c17debcb15028711f3cde9545668c0db3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5052426
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Owners-Override: Nico Weber <thakis@chromium.org>
Reviewed-by: Brendon Tiszka <tiszka@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1229722}