Crash reporting for GMPs being used from the EME call site are not generating
crash reports because they depend on the MediaKeys object calling
GMPService::AddPluginCrashHandler() to associate a window to which the
PluginCrashedEvent is fired. This doesn't work with e10s enabled because the
GMPParent which causes the plugin crash handlers to run is in the chrome
process, but the MediaKeys which adds the handler is in the child process. So
the crash handler is on the GMPServiceChild, but we only run the crash handlers
that were added to the GMPServiceParent in the chrome/parent process.
The solution is to broadcast a message from the chrome process to all the
content processes when a GMP has crashed that causes the GMPServiceChild to
also run its crash handlers.
MozReview-Commit-ID: 8Lek16G9ZGb
