Backout "Bug 860318 - Update keyboard visuals to improve performance.",
since it broke the WVGA support

This reverts commit e69268451116c6b4fea7d7cef3a50ef2d43fa7a8.

Conflicts:
	apps/keyboard/js/render.js
Merge pull request #9894 from RudyLu/keyboard/revert_Bug860318

Backout "Bug 860318 - Update keyboard visuals to improve performance.",