SkMultiPictureDraw API

This CL adds a new API to optimize across multiple SkPicture draw calls.

Note that multiple pictures rendered at once (i.e., picture piles) should be flattened into a single new picture that includes the required clipping on the different layers.

R=bsalomon@google.com, reed@google.com

Author: robertphillips@google.com

Review URL: https://codereview.chromium.org/491313003
5 files changed