Remove obsolete TODO
Remove obsolete TODO

Now we have a new data-grid which we will move to in time, it doesn't
feel worth investing in a lot of util functions for the existing
data-grid.

Bug: none
Change-Id: I4c83ef806d6d289f2b0a952a1930a7f74564fe33
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2667188
Auto-Submit: Jack Franklin <993fcadce4d04090da2fefd557a0995e7966c8d5@chromium.org>
Commit-Queue: Tim van der Lippe <dba8716ee7f8d16236046f74d2167cb94410f6ed@chromium.org>
Reviewed-by: Tim van der Lippe <dba8716ee7f8d16236046f74d2167cb94410f6ed@chromium.org>

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