MacroExpander: bump expansionCount before peeking for "(" BUG=658555 Change-Id: I578b8aff37a116fd7b2b387388311a27bb8a2809 Reviewed-on: https://chromium-review.googlesource.com/403848 Reviewed-by: Geoff Lang <geofflang@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Corentin Wallez <cwallez@chromium.org>