Roll engine 48ad8a08e45f..0bfca375b3f5 (4 commits) (#41314)

git@github.com:flutter/engine.git/compare/48ad8a08e45f...0bfca375b3f5

git log 48ad8a08e45f..0bfca375b3f5 --no-merges --oneline
2019-09-25 yjbanov@google.com Force exit felt tool on sigint, sigterm (flutter/engine#12443)
2019-09-25 skia-flutter-autoroll@skia.org Roll src/third_party/skia 6abaff3041a3..559ffe4a23ce (2 commits) (flutter/engine#12444)
2019-09-25 dworsham@google.com [fuchsia] Wire up OpacityLayer to Scenic (flutter/engine#11322)
2019-09-25 yjbanov@google.com delete golden files; switch to flutter/goldens (flutter/engine#12434)


If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/flutter-engine-flutter-autoroll
Please CC aaclarke@google.com on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md