Add support for websocket PING and PONG frames

Add support for websocket PING and PONG frames

The handling of control frames have been refactored to uniformly
hanlde CLOSE, PING and PONG frames.

Currently this is not tested as I have bot found a good way to test it
yet. It has been somewhat tested with a browser client forcing ping
messages from the server and processing the pong responses from the
browser.

R=ager@google.com, ajohnsen@google.com

BUG=none
TEST=none

Committed: https://code.google.com/p/dart/source/detail?r=7844

[Anders Johnsen, 2012-05-22 08:54:34]

LGTM, however, a bit hard to review.

https://chromiumcodereview.appspot.com/10392195/diff/1/runtime/bin/io.dart
File runtime/bin/io.dart (right):

https://chromiumcodereview.appspot.com/10392195/diff/1/runtime/bin/io.dart#ne...
runtime/bin/io.dart:16: #import("dart:builtin");
You have one guess ^_^

https://chromiumcodereview.appspot.com/10392195/diff/1/runtime/bin/websocket_...
File runtime/bin/websocket_impl.dart (right):

https://chromiumcodereview.appspot.com/10392195/diff/1/runtime/bin/websocket_...
runtime/bin/websocket_impl.dart:250: // Check whether there is any payload. If
not handle callbacks
Weird sentence.

[Mads Ager (google), 2012-05-22 09:04:13]

lgtm

https://chromiumcodereview.appspot.com/10392195/diff/1/runtime/bin/websocket_...
File runtime/bin/websocket_impl.dart (right):

https://chromiumcodereview.appspot.com/10392195/diff/1/runtime/bin/websocket_...
runtime/bin/websocket_impl.dart:296: 2, _controlPayload.length - 2));
Maybe just use four-space indentation here. The arguments are currently aligned
as arguments to write.

[Søren Gjesse, 2012-05-22 10:34:28]

https://chromiumcodereview.appspot.com/10392195/diff/1/runtime/bin/io.dart
File runtime/bin/io.dart (right):

https://chromiumcodereview.appspot.com/10392195/diff/1/runtime/bin/io.dart#ne...
runtime/bin/io.dart:16: #import("dart:builtin");
On 2012/05/22 08:54:34, ajohnsen wrote:
> You have one guess ^_^

Sorry.

https://chromiumcodereview.appspot.com/10392195/diff/1/runtime/bin/websocket_...
File runtime/bin/websocket_impl.dart (right):

https://chromiumcodereview.appspot.com/10392195/diff/1/runtime/bin/websocket_...
runtime/bin/websocket_impl.dart:250: // Check whether there is any payload. If
not handle callbacks
On 2012/05/22 08:54:34, ajohnsen wrote:
> Weird sentence. 

Rephrased.

https://chromiumcodereview.appspot.com/10392195/diff/1/runtime/bin/websocket_...
runtime/bin/websocket_impl.dart:296: 2, _controlPayload.length - 2));
On 2012/05/22 09:04:13, Mads Ager wrote:
> Maybe just use four-space indentation here. The arguments are currently
aligned
> as arguments to write.

Done.