Increase the trace buffer size for the v8_browsing benchmarks

Some of these metrics count up the duration of all trace events
of a specific type contained in the trace, and v8_browsing
enables enough categories that the default sized trace buffer
gets overrun (>100MB).

Requires https://chromium-review.googlesource.com/c/catapult/+/1546568
from catapult to roll into Chrome before landing.

R=perezju@chromium.org,hpayer@chromium.org

Bug: 946517
Change-Id: I1c2b5136dba70d419cd5cbeb721c8e2a539f1002
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1548561
Reviewed-by: Juan Antonio Navarro Pérez <perezju@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Commit-Queue: oysteine <oysteine@chromium.org>
Cr-Commit-Position: refs/heads/master@{#647102}