DevTools: allow zoom in Sources when not paused
DevTools: allow zoom in Sources when not paused

When debugger is paused, holding Ctrl/Cmd highlights
Continue-to-location markers, and DevTools prevents scrolling from
adjusting zoom.

This CL checks whether we are paused somewhere, and allows zooming
via Ctrl-Wheel when not paused.

Bug: 878400
Change-Id: Ibe664f5241914b89fff9c5d7ae90658f2d803918
Reviewed-on: https://chromium-review.googlesource.com/1205537
Reviewed-by: Joel Einbinder <bab755abe9fee48fe544272e55f73517d4e4a725@chromium.org>
Commit-Queue: Erik Luo <26192f5e05d23e5ee959014fb911d780e566545b@chromium.org>
Cr-Original-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#589041}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 085697fefeaee5047b30030016edb95d3bd2bcb7
dart-archive/devtools-frontend,dart-archive/devtools-frontend,dart-archive/devtools-frontend,dart-archive/devtools-frontend,ChromeDevTools/devtools-frontend,dart-archive/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,dart-archive/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend