Revert "Experimental app list: Move custom launcher pages to the end."

Revert "Experimental app list: Move custom launcher pages to the end."

This partially reverts commit 74d1539 (r292900).

(But we keep a small refactor to make it easier to reorder these buttons
in the future.)

BUG=406222
Committed: https://crrev.com/dafbe9581cc48ef683931d9a79890c2b99395712
Cr-Commit-Position: refs/heads/master@{#294062}

[Matt Giuca, 2014-09-09 08:34:44]

mgiuca@chromium.org changed reviewers:
+ calamity@chromium.org

[calamity, 2014-09-09 09:17:24]

lgtm

[Matt Giuca, 2014-09-09 23:45:10]

The CQ bit was checked by mgiuca@chromium.org

[commit-bot: I haz the power, 2014-09-09 23:52:08]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mgiuca@chromium.org/555763002/1

[commit-bot: I haz the power, 2014-09-10 01:23:18]

Committed patchset #1 (id:1) as 4d572a6e4626d8800a0b8f13dca276158333e66d

[commit-bot: I haz the power, 2014-09-10 03:57:18]

Patchset 1 (id:??) landed as
https://crrev.com/dafbe9581cc48ef683931d9a79890c2b99395712
Cr-Commit-Position: refs/heads/master@{#294062}