Fix mojo dart:io IPv6 address printing

Fix mojo dart:io IPv6 address printing

BUG=
R=jamesr@chromium.org

Committed: https://chromium.googlesource.com/external/mojo/+/8920b6de2d0f86438768bd2eeb17bac18519a2d4

[Cutch, 2015-08-24 21:28:06]

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

[jamesr, 2015-08-24 21:28:41]

jamesr@chromium.org changed reviewers:
+ jamesr@chromium.org

[jamesr, 2015-08-24 21:28:41]

lgtm

[jamesr, 2015-08-24 21:29:08]

Please write something like "Fixes #384" in the commit message so it associates
with the GitHub issue correctly

[Cutch, 2015-08-24 21:29:12]

Committed patchset #2 (id:20001) manually as
8920b6de2d0f86438768bd2eeb17bac18519a2d4 (presubmit successful).

[vtl, 2015-08-24 21:39:11]

vtl@google.com changed reviewers:
+ vtl@google.com

[vtl, 2015-08-24 21:39:12]

https://codereview.chromium.org/1309313002/diff/20001/mojo/dart/embedder/io/m...
File mojo/dart/embedder/io/mojo_patch.dart (right):

https://codereview.chromium.org/1309313002/diff/20001/mojo/dart/embedder/io/m...
mojo/dart/embedder/io/mojo_patch.dart:95: var first = '';
drive-by: I'm not sure why something like

var digit = (address[i] * 256 + address[i+1]).toRadixString(16);

wouldn't have been preferable. (This has the benefit of producing "0" for 0
instead of "00", etc.)

[Cutch, 2015-08-24 21:40:27]

On 2015/08/24 21:39:12, vtl wrote:
>
https://codereview.chromium.org/1309313002/diff/20001/mojo/dart/embedder/io/m...
> File mojo/dart/embedder/io/mojo_patch.dart (right):
> 
>
https://codereview.chromium.org/1309313002/diff/20001/mojo/dart/embedder/io/m...
> mojo/dart/embedder/io/mojo_patch.dart:95: var first = '';
> drive-by: I'm not sure why something like
> 
> var digit = (address[i] * 256 + address[i+1]).toRadixString(16);
> 
> wouldn't have been preferable. (This has the benefit of producing "0" for 0
> instead of "00", etc.)

Sure. There are more optimizations to be made too- 0:0:0:0:0:0:0:1 can be
printed as ::1.