Some of the LSP-over-Legacy tests were intermittently failing because the test did not correctly wait for the `setClientCapabilities` request to complete.
The reason for this was that it used the ID `0` (from `_newRequestId`) but so did `setAnalysisRoots`. If the timing was right, the second request would appear to complete when the first did (because the response had id=0) and the test would start before the capabilities had actually been set (and since the test reads them directly off the server, they would be incorrect).
This moves the `_nextRequestId` field down into a base class and updates the helpers for requests like `setAnalysisRoots` to use it too.
Change-Id: Ice44191aad39c7ea81c40e501827557fe563e3d5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/405760
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>
Danny Tuppeny
0d90ccc2ec