Roll engine b9ce2500d9e5..7ea9884ab00e (3 commits) (#40012)

git@github.com:flutter/engine.git/compare/b9ce2500d9e5...7ea9884ab00e

git log b9ce2500d9e5..7ea9884ab00e --no-merges --oneline
2019-09-06 iska.kaushik@gmail.com [flutter_runner] Kernel platform files can now be built in topaz (flutter/engine#12016)
2019-09-06 iska.kaushik@gmail.com [flutter_runner] Plumb Flutter component arguments to the Dart entrypoint (flutter/engine#12026)
2019-09-06 ferhat@gmail.com Fix multi span text ruler cache lookup failure. (flutter/engine#12023)


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

-b9ce2500d9e57389c8b873fbbd016852c8ed8d0a
+7ea9884ab00eb0b63f7793ce8664ae55af484eb1