Roll engine 5e6c005ef1f9..bb78551a0a3d (3 commits) (#42866)

git@github.com:flutter/engine.git/compare/5e6c005ef1f9...bb78551a0a3d

git log 5e6c005ef1f9..bb78551a0a3d --no-merges --oneline
2019-10-16 skia-flutter-autoroll@skia.org Roll src/third_party/skia 59e72b71b5cf..4e11526e3d7e (10 commits) (flutter/engine#13174)
2019-10-16 hterkelsen@users.noreply.github.com Fix type error in SkVertices (flutter/engine#13157)
2019-10-16 bkonyi@google.com Roll src/third_party/dart 41b65b27c2..ed1e0e199e (18 commits)


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 franciscojma@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

-5e6c005ef1f96001513625ab296c3df8db5ec141
+bb78551a0a3d5c7e227ee0b6e2836b611158f383