Convert CC scheduler logic to use base::TimeTicks/Delta instead of doubles

Convert CC scheduler logic to use base::TimeTicks/Delta instead of doubles

Instead of using double seconds, this converts the scheduler and timer logic
in libcc to use base::TimeTicks and base::TimeDelta. This puts the units in
the type system instead of variable names and comments making second/millisecond
confusion less likely and integrates better with the rest of chromium.

BUG=


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=157783

[nduca, 2012-09-20 03:52:52]

lgtm

[commit-bot: I haz the power, 2012-09-20 05:30:19]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/jamesr@chromium.org/10956006/4001

[commit-bot: I haz the power, 2012-09-20 16:33:50]

Change committed as 157783