This adds completion support in the class header. Support for completion
in the body will be added in a separate CL.
Please look carefully at the tests to ensure that there aren't holes in
the coverage.
Change-Id: I189f25fbb90f43b4d8993622d5eb025d3160bef1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/467920
Reviewed-by: Kallen Tu <kallentu@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>
Brian Wilkerson
ba35276ae2