Allow SkCanvas to be initialized to force conservative rasterclips. This has the following effects:
1. Queries to the current clip will be conservatively large. This can mean the quickReject may return false more often.
2. The conservative clips mean less work is done.
3. Enabled by default for Gpu, Record, and NoSaveLayer canvases.
4. API is private for now.
R=robertphillips@google.com, bsalomon@google.com, mtklein@google.com, junov@google.com
Author: reed@google.com
Review URL: https://codereview.chromium.org/541593005
12 files changed