Rename finishOpList to finishFlush and call it less frequently

It is expected that this will fix the Vulkan perf regression associated with splitting up the opLists

Change-Id: I1bbb6f71745bb08d4a8c2f7810e5ab84cca75e84
Reviewed-on: https://skia-review.googlesource.com/16901
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
7 files changed