Fix stylelint-config-standard issues in ui/treeoutline.css
Fix stylelint-config-standard issues in ui/treeoutline.css

R=d8d88e7d7e77f69e23d1d1432231196fb8e02a62@chromium.org

Bug: chromium:108314
Change-Id: Idc03f89d97d618c4a083d7035d64e2b2ffa8eec0
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2282354
Commit-Queue: Yang Guo <1cf0af8245a3a17a632a2c73531392b0f9761c76@chromium.org>
Commit-Queue: Alex Rudenko <d8d88e7d7e77f69e23d1d1432231196fb8e02a62@chromium.org>
Auto-Submit: Yang Guo <1cf0af8245a3a17a632a2c73531392b0f9761c76@chromium.org>
Reviewed-by: Alex Rudenko <d8d88e7d7e77f69e23d1d1432231196fb8e02a62@chromium.org>

ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend