Fix the remaining strong mode warnings.

Fix the remaining strong mode warnings.

These ones require explicit casts to work around limitations in some
SDK methods and expectAsync() in test. Ideally, we will change those
APIs to be more soundly typed. Until then, this gets the package clean.

R=nweiz@google.com

Committed: https://github.com/dart-lang/stack_trace/commit/b528ff4a6b8cfcf53a67dde3b5722c863a0f2350

[Bob Nystrom, 2016-04-07 22:55:40]

rnystrom@google.com changed reviewers:
+ nweiz@google.com

[nweiz, 2016-04-08 00:24:03]

https://codereview.chromium.org/1871763002/diff/1/test/chain/chain_test.dart
File test/chain/chain_test.dart (right):

https://codereview.chromium.org/1871763002/diff/1/test/chain/chain_test.dart#...
test/chain/chain_test.dart:54: // TODO(rnystrom): Remove this cast if
expectAsync() gets a better type.
I generally haven't been making tests strong mode clean yet, since test itself
isn't strong mode clean and there's not a great way to ensure that they stay
clean.

[nweiz, 2016-04-08 00:24:48]

lgtm

[Bob Nystrom, 2016-04-08 00:25:44]

Description was changed from

==========
Fix the remaining strong mode warnings.

These ones require explicit casts to work around limitations in some
SDK methods and expectAsync() in test. Ideally, we will change those
APIs to be more soundly typed. Until then, this gets the package clean.
==========

to

==========
Fix the remaining strong mode warnings.

These ones require explicit casts to work around limitations in some
SDK methods and expectAsync() in test. Ideally, we will change those
APIs to be more soundly typed. Until then, this gets the package clean.

R=nweiz@google.com

Committed:
https://github.com/dart-lang/stack_trace/commit/b528ff4a6b8cfcf53a67dde3b5722...
==========

[Bob Nystrom, 2016-04-08 00:25:45]

Committed patchset #1 (id:1) manually as
b528ff4a6b8cfcf53a67dde3b5722c863a0f2350 (presubmit successful).