Fix DoubleLinkedListQueue misbehavior on concurrent modification.

Fix DoubleLinkedListQueue misbehavior on concurrent modification.

Documented forEachEntry, firstEntry and lastEntry.
Made forEachEntry more useful by making it compatible with removing and adding
around the current entry, and documented how it interacts.

BUG= http://dartbug.com/27920
R=floitsch@google.com

Committed: https://github.com/dart-lang/sdk/commit/9412b54f1fcb24f3cdd7fa9a32833f981cf2ce63

[Lasse Reichstein Nielsen, 2016-11-30 08:08:47]

lrn@google.com changed reviewers:
+ floitsch@google.com

[floitsch, 2016-12-01 18:31:10]

LGTM.

We got requests from the dart2js team, if these concurrent-modification checks
couldn't be assert-mode only.
We might want to go through our libraries and change them.

https://codereview.chromium.org/2540993002/diff/1/sdk/lib/collection/queue.dart
File sdk/lib/collection/queue.dart (right):

https://codereview.chromium.org/2540993002/diff/1/sdk/lib/collection/queue.da...
sdk/lib/collection/queue.dart:409: DoubleLinkedQueueEntry<E> lastEntry() {
not a getter?
argh :(

[Lasse Reichstein Nielsen, 2016-12-06 08:32:08]

Description was changed from

==========
Fix DoubleLinkedListQueue misbehavior on concurrent modification.

Documented forEachEntry, firstEntry and lastEntry.
Made forEachEntry more useful by making it compatible with removing and adding
around the current entry, and documented how it interacts.

BUG= http://dartbug.com/27920
==========

to

==========
Fix DoubleLinkedListQueue misbehavior on concurrent modification.

Documented forEachEntry, firstEntry and lastEntry.
Made forEachEntry more useful by making it compatible with removing and adding
around the current entry, and documented how it interacts.

BUG= http://dartbug.com/27920
R=floitsch@google.com

Committed:
https://github.com/dart-lang/sdk/commit/9412b54f1fcb24f3cdd7fa9a32833f981cf2ce63
==========

[Lasse Reichstein Nielsen, 2016-12-06 08:32:10]

Committed patchset #1 (id:1) manually as
9412b54f1fcb24f3cdd7fa9a32833f981cf2ce63 (presubmit successful).