Factor out a Runner class from executable.dart.

Factor out a Runner class from executable.dart.

This is useful as an object because it provides all the private methods with
full access to the configuration, the engine, and the loader without having to
pass them around or create top-level variables. It also creates a cleaner
distinction between receiving a signal and closing various components.

R=kevmoo@google.com

Committed: https://github.com/dart-lang/test/commit/218f9925609a8835caf66cbe42bc5f7bb005e94a

[kevmoo, 2015-07-14 01:44:16]

LGTM w/ one nit

https://codereview.chromium.org/1239613002/diff/1/lib/src/executable.dart
File lib/src/executable.dart (right):

https://codereview.chromium.org/1239613002/diff/1/lib/src/executable.dart#new...
lib/src/executable.dart:19: import 'util/io.dart';
unused import

[nweiz, 2015-07-14 19:42:31]

Code review changes

[nweiz, 2015-07-14 19:42:51]

https://codereview.chromium.org/1239613002/diff/1/lib/src/executable.dart
File lib/src/executable.dart (right):

https://codereview.chromium.org/1239613002/diff/1/lib/src/executable.dart#new...
lib/src/executable.dart:19: import 'util/io.dart';
On 2015/07/14 01:44:16, kevmoo wrote:
> unused import

Done.

[nweiz, 2015-07-14 19:42:59]

Committed patchset #2 (id:20001) manually as
218f9925609a8835caf66cbe42bc5f7bb005e94a (presubmit successful).