MacViews: Fix duplicate definition of ValidationMessageBubble::ShowAndCreate

MacViews: Fix duplicate definition of ValidationMessageBubble::ShowAndCreate

Refactor into a virtual method on TabDialogs, with overrides for Views and
Cocoa.
ValidationMessageBubble is moved out of chrome namespace to be more
consistent with other dialogs.

BUG=425229
Committed: https://crrev.com/49f9a7a9dc186798a76eac37e731e52b3a574af9
Cr-Commit-Position: refs/heads/master@{#313411}

[Andre, 2015-01-23 22:06:21]

Patchset #1 (id:1) has been deleted

[Andre, 2015-01-23 23:38:46]

sky@ please review.

[Andre, 2015-01-23 23:38:58]

andresantoso@chromium.org changed reviewers:
+ sky@chromium.org

[Andre, 2015-01-27 23:05:46]

Scott, ping?

[sky, 2015-01-27 23:56:12]

LGTM

[Andre, 2015-01-27 23:58:52]

The CQ bit was checked by andresantoso@chromium.org

[commit-bot: I haz the power, 2015-01-27 23:59:31]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/867323005/20001

[commit-bot: I haz the power, 2015-01-28 00:03:54]

Committed patchset #1 (id:20001)

[commit-bot: I haz the power, 2015-01-28 00:05:47]

Patchset 1 (id:??) landed as
https://crrev.com/49f9a7a9dc186798a76eac37e731e52b3a574af9
Cr-Commit-Position: refs/heads/master@{#313411}