Merge pull request #19299 from nullaus/bug982295-browser-api

bug 982295 - Use new Browser API download method. r=benfrancis(cherry picked from commit 901646a3279c66daa7621bebb62641779d8ae22c)
Merge pull request #20381 from nullaus/v2.0

Merge pull request #19299 from nullaus/bug982295-browser-api