3360d861e [web] filter test targets; cache host.dart compilation (flutter/engine#12445) (#41321)

git@github.com:flutter/engine.git/compare/efb7bf434f2c...3360d861e5cf

git log efb7bf434f2c..3360d861e5cf --no-merges --oneline
2019-09-25 yjbanov@google.com [web] filter test targets; cache host.dart compilation (flutter/engine#12445)


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

bin/internal/engine.version

-efb7bf434f2c993dc0f44a83fa13efcda127526a
+3360d861e5cf18fc330ff11c6b15cee972fc1762