Ripple effect does not end if button is dragged

[RafaelMarinheiro]

System Info:

• Windows 7 x64
• Google Chrome Version 43.0.2357.130 m

How to reproduce:

1. Go to Paper-Button Demo Page
2. Select any text on the page.
3. Click and drag any button that uses the ripple effect.
4. Repeat step 3 multiple times.