[sync] Fix behavior of "Use default settings" / "Advanced" links

[sync] Fix behavior of "Use default settings" / "Advanced" links

This CL fixes the behavior seen while switching between the "Use default
settings" / "Advanced" modes of the sync setup dialog.

BUG=316547
TEST=Switch between the "Use default settings" and "Advanced" modes. OK button must receive focus.
R=rogerta@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=234650

[Raghu Simha, 2013-11-11 23:51:16]

Roger, please review. Thanks.

[Raghu Simha, 2013-11-12 19:29:31]

Ping.

[Roger Tawa OOO till Jul 10th, 2013-11-12 21:05:33]

lgtm

[commit-bot: I haz the power, 2013-11-12 21:11:43]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rsimha@chromium.org/69723002/1

[commit-bot: I haz the power, 2013-11-12 22:07:19]

Sorry for I got bad news for ya.
Compile failed with a clobber build on linux_chromeos_clang.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_chro...
Your code is likely broken or HEAD is junk. Please ensure your
code is not broken then alert the build sheriffs.
Look at the try server FAQ for more details.

[Raghu Simha, 2013-11-12 22:19:04]

Committed patchset #1 manually as r234650 (presubmit successful).