This CL aborts completion requests (returns empty list of completions)
if either a newer completion request is received
or the source changes after the completion request was received.
In addition, I wrapped calls to AnalysisFutureHelper computeAsync
in exception handlers so that it will be easier to track async exceptions
back to the code that requested the computations.
R=brianwilkerson@google.com
Review URL: https://codereview.chromium.org/1685653002 .
danrubel
3fc06a4aa7