Run clang-tidy modernize-use-nullptr on //ui/views

This is a run of
run-clang-tidy.py -checks="-*,modernize-use-nullptr" -header-filter=ui/views/* \\src\\ui\\views\\

BUG=940732
TBR=sadrul@chromium.org
This CL was uploaded by git cl split.

R=sadrul@chromium.org

Change-Id: I81a954e6e1032d4eb883e437e4416bb8a72d635f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1529880
Reviewed-by: Robert Liao <robliao@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Commit-Queue: Robert Liao <robliao@chromium.org>
Auto-Submit: Robert Liao <robliao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#642036}
2 files changed