Fixes tests lib_2/html/event_customerevent_test
co19_2/LibtTest/html/Document/window_A01_t01
JS inline incorrectly uses the converted html name for attributes for
getters. Similarly, dynamics do not need to be marked as nullable as
they are already nullable. This also fixes some of the nullability logic
for conversion input and output.
Change-Id: I77efde95a4e5d52461b3412f8650578e967ca5cd
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/135201
Reviewed-by: Sigmund Cherem <sigmund@google.com>
Commit-Queue: Srujan Gaddam <srujzs@google.com>
Srujan Gaddam
e7ee11a95b