Wait for all log entries to be printed before exiting "pub build".

Wait for all log entries to be printed before exiting "pub build".

Previously, we could drop messages on the floor if too many were
emitted and the actual building was quick enough.

R=rnystrom@google.com
BUG=16242
Committed: https://code.google.com/p/dart/source/detail?r=32141

[Bob Nystrom, 2014-01-28 22:41:14]

https://codereview.chromium.org/148213009/diff/1/sdk/lib/_internal/pub/lib/sr...
File sdk/lib/_internal/pub/lib/src/utils.dart (right):

https://codereview.chromium.org/148213009/diff/1/sdk/lib/_internal/pub/lib/sr...
sdk/lib/_internal/pub/lib/src/utils.dart:131: /// an event during the span of
time it takes for [new Timer] to fire.
This is gross. Barback should give us a better API so that we can know when it's
done.

[nweiz, 2014-01-28 23:04:05]

https://codereview.chromium.org/148213009/diff/1/sdk/lib/_internal/pub/lib/sr...
File sdk/lib/_internal/pub/lib/src/utils.dart (right):

https://codereview.chromium.org/148213009/diff/1/sdk/lib/_internal/pub/lib/sr...
sdk/lib/_internal/pub/lib/src/utils.dart:131: /// an event during the span of
time it takes for [new Timer] to fire.
On 2014/01/28 22:41:14, Bob Nystrom wrote:
> This is gross. Barback should give us a better API so that we can know when
it's
> done.

I couldn't come up with a good way to do that. The log entries are
(intentionally) kept out-of-band with respect to the call to [getAllAssets], and
I don't think there's a clean way to put them in-band. I guess we could add a
[Barback.close] method that closed out all the outgoing streams, but this seems
like a strange reason to add that method.

[nweiz, 2014-01-29 20:23:30]

ptal

[Bob Nystrom, 2014-01-29 20:56:46]

lgtm

https://codereview.chromium.org/148213009/diff/20001/pkg/barback/lib/src/pack...
File pkg/barback/lib/src/package_graph.dart (right):

https://codereview.chromium.org/148213009/diff/20001/pkg/barback/lib/src/pack...
pkg/barback/lib/src/package_graph.dart:61: final _logController = new
StreamController<LogEntry>.broadcast(sync: true);
Don't forget to bump the barback version.

[nweiz, 2014-01-29 21:26:55]

https://codereview.chromium.org/148213009/diff/20001/pkg/barback/lib/src/pack...
File pkg/barback/lib/src/package_graph.dart (right):

https://codereview.chromium.org/148213009/diff/20001/pkg/barback/lib/src/pack...
pkg/barback/lib/src/package_graph.dart:61: final _logController = new
StreamController<LogEntry>.broadcast(sync: true);
On 2014/01/29 20:56:46, Bob Nystrom wrote:
> Don't forget to bump the barback version.

Done.

[nweiz, 2014-01-29 21:28:12]

Committed patchset #3 manually as r32141 (presubmit successful).