Roll engine c84fad959284..e0fe8342889c (2 commits) (#48976)

https://github.com/flutter/engine/compare/c84fad959284...e0fe8342889c

git log c84fad959284..e0fe8342889c --first-parent --oneline
2020-01-16 skia-flutter-autoroll@skia.org Roll src/third_party/dart 515d4bd7adb1..009537bbf0ff (1 commits) (flutter/engine#15687)
2020-01-16 skia-flutter-autoroll@skia.org Roll fuchsia/sdk/core/linux-amd64 from UlOSN... to YPYqb... (flutter/engine#15689)


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 jimgraham@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

-c84fad95928414ee1bb65dfc51d97434dc5cfd10
+e0fe8342889c9f0ba206891e66688d7c137998ea