Revert of athena: Add a minimized state for the home-card.

Revert of athena: Add a minimized state for the home-card. (https://codereview.chromium.org/394043002/)

Reason for revert:
it broke "athena_unittests,steps" on "Linux ChromiumOS Tests (1)":
http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Tests%20%281%29/builds/45720.

Original issue's description:
> athena: Add a minimized state for the home-card.
> 
> The home-card can be in a minimized state. In this state, only a narrow line
> is displayed at the bottom of the screen, and dragging it up shows the overview
> mode. When a window is selected in the overview mode, the home-card is minimized
> again.
> 
> BUG=381224
> R=mukai@chromium.org, oshima@chromium.org
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=283539

TBR=mukai@chromium.org,oshima@chromium.org,sadrul@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=381224
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=283564

[kuan, 2014-07-16 23:04:47]

Created Revert of athena: Add a minimized state for the home-card.

[commit-bot: I haz the power, 2014-07-16 23:07:25]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/kuan@chromium.org/391383004/1

[commit-bot: I haz the power, 2014-07-16 23:12:02]

Change committed as 283564