The {NUMBER} regexp only allowed one, leading to occasional test
failures such as:
https://build.chromium.org/p/client.v8/builders/V8%20Mac%20-%20debug/builds/17156

Bug: 
Change-Id: I25a08b80640d9af19ba70c61c846163685f1cb82
Reviewed-on: https://chromium-review.googlesource.com/753322Reviewed-by: Franziska Hinkelmann <franzih@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49109}