Add Puppeteer sourcemaps to BUILD.gn to fix network errors
Add Puppeteer sourcemaps to BUILD.gn to fix network errors

Bug: none
Change-Id: I0e25284ca66ab229e48cf7b9a466043865bfb0de
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2886922
Auto-Submit: Jack Franklin <993fcadce4d04090da2fefd557a0995e7966c8d5@chromium.org>
Reviewed-by: Tim van der Lippe <dba8716ee7f8d16236046f74d2167cb94410f6ed@chromium.org>
Commit-Queue: Jack Franklin <993fcadce4d04090da2fefd557a0995e7966c8d5@chromium.org>

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