Split up opLists (take 3)

Reland of: https://skia-review.googlesource.com/c/11581/ (Split up opLists)

https://skia-review.googlesource.com/c/13860/ (Make InstancedRendering more opList-splitting friendly) has landed so this should be good for another attempt.

TBR=egdaniel@google.com
Change-Id: I2a09729342bb035af3a16807c1895adbae432ade
Reviewed-on: https://skia-review.googlesource.com/14186
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
12 files changed