Check if we should exit high precision timer mode after all requestAnimationFrame callbacks have been processed.

This should make our rendering more efficient (instead of relying on the default timer which keep 1ms precision mode active for up to 90s).
- Lowers CPU usage
- Lowers power consumption

layout/base/nsRefreshDriver.cpp

@@ -1735,6 +1735,9 @@ nsRefreshDriver::Tick(int64_t aNowEpoch, TimeStamp aNowTime)
     mPostRefreshObservers[i]->DidRefresh();
   }
 
+  // Check if we should exit high precision timer mode.
+  ConfigureHighPrecision();
+  
   NS_ASSERTION(mInRefresh, "Still in refresh");
 }