Complex clipPath accounting

Add a clipPath heuristic to SkPathCounter, and extend
SkPictureGpuAnalyzer to support external clipPath() op accounting.

BUG=skia:5347
R=reed@google.com,mtklein@google.com,senorblanco@chromium.org,bsalomon@google.com
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2000423005

Review-Url: https://codereview.chromium.org/2000423005
4 files changed