Merge pull request #9895 from RudyLu/keyboard/Bug860318-layout_improvement_commit2

Bug 860318 - Update keyboard visuals to improve performance. r=timdream(cherry picked from commit e6579f1a2a7d980ae93bfa4ffdcbdf47eac8ae97)

Conflicts:
	apps/keyboard/js/render.js
	apps/keyboard/style/keyboard.css