Remove unused menu item types.

Remove unused menu item types.

two_button_menu_item was added in https://codereview.chromium.org/608283004
but it is not used anymore due to menu button removal from the menu popup.

four_button_menu_item was also added to support menu button inside the menu
popup.

BUG=None

Committed: https://crrev.com/8418bc1910647ab3364118b26596303170d58e05
Cr-Commit-Position: refs/heads/master@{#317103}

[aurimas (slooooooooow), 2015-02-19 01:51:15]

aurimas@chromium.org changed reviewers:
+ tedchoc@chromium.org

[aurimas (slooooooooow), 2015-02-19 01:51:15]

tedchoc: PTAL

[Ted C, 2015-02-19 19:13:17]

lgtm

[aurimas (slooooooooow), 2015-02-19 19:14:49]

The CQ bit was checked by aurimas@chromium.org

[commit-bot: I haz the power, 2015-02-19 19:15:21]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/934353003/20001

[commit-bot: I haz the power, 2015-02-19 19:35:22]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-02-19 19:35:54]

Patchset 2 (id:??) landed as
https://crrev.com/8418bc1910647ab3364118b26596303170d58e05
Cr-Commit-Position: refs/heads/master@{#317103}