Make run_benchmark timeout configurable during pixel diff runs
Make run_benchmark timeout configurable during pixel diff runs

Bug: skia:6957
Change-Id: Id3beeeb2e44a55da72a9101a9b1ab80b0284e581
Reviewed-on: https://skia-review.googlesource.com/36402
Reviewed-by: Ben Wagner <3ef7217be91069877d94f7907ce5479000772cd3@google.com>
Commit-Queue: Ravi Mistry <9fa2e7438b8cb730f96b74865492597170561628@google.com>

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot