TypeScriptify media MainView
TypeScriptify media MainView

R=38944668e9e2ca98ccd0275b53370f90fa55c113@chromium.org

Bug: 1011811
Change-Id: Idd138a82a2ef2d087c35f8134ccce669358d3675
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2463343
Reviewed-by: Simon Zünd <38944668e9e2ca98ccd0275b53370f90fa55c113@chromium.org>
Commit-Queue: Paul Lewis <8915f5d5c39a08c5a3e8a8d7314756e4580816f9@chromium.org>

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