feat: Discover more events dynamically
feat: Discover more events dynamically

There are sometimes events without an associated "on" property in the
object.  For these, we can shim addEventListener and listen for any
event the app is listening for, and thus discover additional events.

Change-Id: I017599381755e5fb095cd9f989591b0595ac0897

shaka-project/eme_logger,shaka-project/eme_logger