Rename GrOpList::reset to endFlush

Bug: skia:7111
Change-Id: I9e48224c7edcc51bd0368cb7c115acbc3bf8da16
Reviewed-on: https://skia-review.googlesource.com/54500
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
9 files changed