Adding Chromium authors to the AUTHORS file

Adding Chromium authors to the AUTHORS file.

Some Googlers commit code into Skia using their chromium.org accounts. 
The Chromium AUTHORS file has a similar entry:
http://src.chromium.org/viewvc/chrome/trunk/src/AUTHORS

(SkipBuildbotRuns)

NOTRY=true
BUG=skia:2072
TBR=

Committed: http://code.google.com/p/skia/source/detail?r=13271

[hcm, 2014-01-31 19:09:24]

LGTM

[rmistry, 2014-01-31 19:10:17]

The CQ bit was checked by rmistry@google.com

[commit-bot: I haz the power, 2014-01-31 19:10:28]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-01-31 19:10:29]

No LGTM from a valid reviewer yet. Only full committers are accepted.
Even if an LGTM may have been provided, it was from a non-committer or
a lowly provisional committer, _not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[commit-bot: I haz the power, 2014-01-31 19:10:34]

CQ bit was unchecked on CL. Ignoring.

[rmistry, 2014-01-31 19:12:00]

The CQ bit was checked by rmistry@google.com

[commit-bot: I haz the power, 2014-01-31 19:12:38]

CQ is trying da patch. Follow status at
https://skia-tree-status.appspot.com/cq/rmistry@google.com/146853004/30001

[commit-bot: I haz the power, 2014-01-31 19:12:45]

CQ bit was unchecked on CL. Ignoring.

[commit-bot: I haz the power, 2014-01-31 19:12:45]

Change committed as 13271