Fix issue 20133: do not crash if debug port is illegal.

Fix issue 20133: do not crash if debug port is illegal.

R=asiva@google.com

Committed: https://code.google.com/p/dart/source/detail?r=41155

[srdjan, 2014-10-15 22:09:44]

srdjan@google.com changed reviewers:
+ asiva@google.com

[siva, 2014-10-15 22:58:42]

LGTM with one comment.

https://codereview.chromium.org/657213002/diff/1/runtime/bin/dbg_connection.cc
File runtime/bin/dbg_connection.cc (right):

https://codereview.chromium.org/657213002/diff/1/runtime/bin/dbg_connection.c...
runtime/bin/dbg_connection.cc:337: exit(255);
This file seems to use FATAL("....") whenever it gets an error, see above.

[srdjan, 2014-10-16 15:47:46]

https://codereview.chromium.org/657213002/diff/1/runtime/bin/dbg_connection.cc
File runtime/bin/dbg_connection.cc (right):

https://codereview.chromium.org/657213002/diff/1/runtime/bin/dbg_connection.c...
runtime/bin/dbg_connection.cc:337: exit(255);
On 2014/10/15 22:58:41, siva wrote:
> This file seems to use FATAL("....") whenever it gets an error, see above.

FATAL crashes the VM, I assume it is used for the cases that cannot occur in
normal operation. Since the failure of creating a listener_fd_ can occur when
passing wrong arguments, this CL reports an error without crashing the VM.

[srdjan, 2014-10-16 17:08:25]

Committed patchset #1 (id:1) manually as r41155 (presubmit successful).