We were using a boolean before, which makes the meaning non-obvious
when passed as a parameter. With the enum, you actually have to use
{kRuntimeExceptionSupport} or {kNoRuntimeExceptionSupport}.

R=mtrofin@chromium.org

Change-Id: Iaf5a7b6f1b446d4c3e16e044a6055d923d3b0b49
Reviewed-on: https://chromium-review.googlesource.com/660738
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Mircea Trofin <mtrofin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47969}