Provide mechanism to close immediately to Dart bindings

- Rename "nodefer" to "immediate" (gets rid of double negative in "nodefer: false").
- Immediate close means that anything pending will be discarded.
- Plumb immediate all the way down to the handle watcher close call.
- When an EventStream is closed because no one is listening for events, close immediately.
- Don't call Dart_NewSendPort with ILLEGAL_PORT in sky embedder.
- Bump DEPS to include fixes for Dart_NewSendPort and profiler signal handler executing after shared object is unloaded.
- Fixes https://github.com/domokit/mojo/issues/79

R=zra@google.com

Committed: https://chromium.googlesource.com/external/mojo/+/5d2f53716182a5fe260342ab04f4808c409a289f

[Cutch, 2015-04-07 19:28:13]

johnmccutchan@google.com changed reviewers:
+ zra@google.com

[zra, 2015-04-07 19:49:46]

lgtm with questions

https://codereview.chromium.org/1060193002/diff/80001/mojo/public/dart/src/ev...
File mojo/public/dart/src/event_stream.dart (right):

https://codereview.chromium.org/1060193002/diff/80001/mojo/public/dart/src/ev...
mojo/public/dart/src/event_stream.dart:107: void _localClose({bool immediate:
false}) {
Is this needed for something?

https://codereview.chromium.org/1060193002/diff/80001/mojo/public/dart/src/st...
File mojo/public/dart/src/stub.dart (right):

https://codereview.chromium.org/1060193002/diff/80001/mojo/public/dart/src/st...
mojo/public/dart/src/stub.dart:55: if (_isClosing) {
Was this code running when _isClosing was already false?

[Cutch, 2015-04-07 19:52:13]

https://codereview.chromium.org/1060193002/diff/80001/mojo/public/dart/src/ev...
File mojo/public/dart/src/event_stream.dart (right):

https://codereview.chromium.org/1060193002/diff/80001/mojo/public/dart/src/ev...
mojo/public/dart/src/event_stream.dart:107: void _localClose({bool immediate:
false}) {
On 2015/04/07 19:49:46, zra wrote:
> Is this needed for something?

It's not needed, I was just passing the value down. I'll remove it for now.

https://codereview.chromium.org/1060193002/diff/80001/mojo/public/dart/src/st...
File mojo/public/dart/src/stub.dart (right):

https://codereview.chromium.org/1060193002/diff/80001/mojo/public/dart/src/st...
mojo/public/dart/src/stub.dart:55: if (_isClosing) {
On 2015/04/07 19:49:46, zra wrote:
> Was this code running when _isClosing was already false?

Yes, the then clause on line 98 could sometimes run before the then clause on
lines 55 or 68.

[Cutch, 2015-04-07 20:00:07]

Committed patchset #7 (id:120001) manually as
5d2f53716182a5fe260342ab04f4808c409a289f (presubmit successful).