Generate cache traffic each iteration

The old timing system would generate cache traffic
for the first drawing of the picture caching everyting
on the GPU side. Further iterations would just use the cache.

This change forces cache traffic to be generated each iteration.

BUG=skia:7515

Change-Id: I0d857e123796cdc7d655634446082598bef3f962
Reviewed-on: https://skia-review.googlesource.com/103021
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Herb Derby <herb@google.com>
4 files changed