mdProgressLinear: Substantial CPU use while disabled

[justinappler]

Actual behavior:

• When ng-disabled is set to true on the mdProgressLinear component, substantial CPU is used while the page is idle. This can be easily reproduced by watching the Chrome Task Manager while the disabled mdProgressLinear is on the page and then removing it and checking again.
• In a barebones Plnkr, I see about a 10% CPU usage difference between the component being present and disabled vs not present. In my real world app, it can get as high as a 30-40% usage difference.

CodePen or Steps to reproduce the issue:

• https://embed.plnkr.co/h3UQqnp0LK9GxPlfjOJv/

Angular Versions:

• Angular Version: 1.5.5
• Angular Material Version: 1.1.0-rc5

Additional Information:

• Browser Type: Chrome
• Browser Version: 50
• OS: OSX

[crisbeto]

I couldn't see any change in CPU usage between enabled and disabled. I don't think just looking at the task manager is the best way to diagnose these types of issues, since it can be anything else on that page causing it (e.g. Plunkr's own JS or an extension that you're running). That being said, we could improve the disabled state, because at the moment, the element is still animating in the background.