Add builder tag for Safari 6.2 slave. Update status files for Safari 6.2.

BUG=
R=ricow@google.com

Review URL: https://codereview.chromium.org//679153002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41323 260f80e4-7a28-3924-810f-c04153c831b5
Remove EngineTestCase.createSource().

R=brianwilkerson@google.com
BUG=

Review URL: https://codereview.chromium.org//679173002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41324 260f80e4-7a28-3924-810f-c04153c831b5
Pass builder-tag to test.py on dart2js bots.

BUG=

Review URL: https://codereview.chromium.org//686453002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41325 260f80e4-7a28-3924-810f-c04153c831b5
Fix deadlock that can occur while handling service messages at a breakpoint.

Deadlock looks like:

  Regular Isolate
  -> paused at breakpoint in debug message loop
  -> holds debug message queue lock to get message notifications
  -> handles an service message
  -> waits for portmap lock to send response

  Service Isolate
  -> receives request for paused isolate
  -> holds portmap lock to send message
  -> runs custom message notifier to wake debug message loop
  -> waits for debug message queue lock

I've solved this by releasing the debug message queue lock while
handling service messages.  This requires me to poll for new service
messages after reacquiring the debug message queue lock to make sure I
haven't dropped any notifications.

It's a little weird that the embedder (runtime/bin) needs to be aware
of the locking in the core vm (runtime/vm), but this seemed like the
simplest fix for now.

BUG=
R=johnmccutchan@google.com

Review URL: https://codereview.chromium.org//629533002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41326 260f80e4-7a28-3924-810f-c04153c831b5
Remove unnecessary List creation

R=scheglov@google.com

Review URL: https://codereview.chromium.org//677303002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41327 260f80e4-7a28-3924-810f-c04153c831b5