We are pushing out a new Widevine CDM version, so we need to update the CDM
downloader to download the new version if the GMP AUS server is down.
Note that the existing code won't download a CDM/GMP using the fallback path if
a CDM/GMP is not already installed.
MozReview-Commit-ID: 6eF4QupkU77
--HG--
extra : rebase_source : ce0aafd4e3e07cfc1fc96fb5523ca69b0dddbac9
James Cheng
Chris Pearce
Dale Harvey