Bug 788549 Part 1: Throttled animations should not claim that their style rule is up to date r=dbaron, nrc

layout/style/nsAnimationManager.cpp

@@ -202,7 +202,6 @@ ElementAnimations::EnsureStyleRuleFor(TimeStamp aRefreshTime,
   }
 
   if (aIsThrottled) {
-    mStyleRuleRefreshTime = aRefreshTime;
     return;
   }