Graph width is now managed by the Graph instead of the GraphView,
which simplifies some interfaces.

Change-Id: If78bc9a469cc8369bc75695a6612627103036bc8
Notry: true
Bug: v8:7327
Reviewed-on: https://chromium-review.googlesource.com/c/1398227Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58618}