Roll engine 7ed9c9fc5885..6a1f093398c6 (5 commits) (#44419)

git@github.com:flutter/engine.git/compare/7ed9c9fc5885...6a1f093398c6

git log 7ed9c9fc5885..6a1f093398c6 --no-merges --oneline
2019-11-08 skia-flutter-autoroll@skia.org Roll src/third_party/skia 345a2735e2c8..76eaab6b8cef (18 commits) (flutter/engine#13745)
2019-11-08 gw280@google.com Only specify --no-link-platform when not specifying --aot, roll dart-lang sdk (flutter/engine#13742)
2019-11-08 ferhat@gmail.com Don't run engine tests under vm (causing warnings) (flutter/engine#13737)
2019-11-07 christopherfujino@gmail.com Switch to Cirrus Dockerfile as CI (flutter/engine#13440)
2019-11-07 matthew-carroll@users.noreply.github.com Removed scary experimental warnings for new embedding. (#44314) (flutter/engine#13738)


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 garyq@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

bin/internal/engine.version

-7ed9c9fc5885fbf76cdda22331cb07f1da75ccf5
+6a1f093398c6dc575a7a85ad66d5851316b0c2cb