Don't warn when jsSchedulingOverhead is negative

Summary:This commit modifies the jsSchedulingOverhead warning to only fire if the JS clock is more than 5 seconds ahead of the native clock. This fixes the issue in #1598 for the common case when there's only a minor difference between the two clocks, while still keeping a sanity check if they're extremely off.

cc nicklockwood tadeuzagallo
Closes https://github.com/facebook/react-native/pull/5731

Differential Revision: D3014985

Pulled By: tadeuzagallo

fb-gh-sync-id: bf57e48b7d97ad02d2aefb6e5aac845824a6fdb0
shipit-source-id: bf57e48b7d97ad02d2aefb6e5aac845824a6fdb0

React/Modules/RCTTiming.m

@@ -174,15 +174,7 @@ RCT_EXPORT_METHOD(createTimer:(nonnull NSNumber *)callbackID
     return;
   }
 
-  NSTimeInterval jsSchedulingOverhead = -jsSchedulingTime.timeIntervalSinceNow;
-  if (jsSchedulingOverhead < 0) {
-    RCTLogWarn(@"jsSchedulingOverhead (%ims) should be positive", (int)(jsSchedulingOverhead * 1000));
-
-    /**
-     * Probably debugging on device, set to 0 so we don't ignore the interval
-     */
-    jsSchedulingOverhead = 0;
-  }
+  NSTimeInterval jsSchedulingOverhead = MAX(-jsSchedulingTime.timeIntervalSinceNow, 0);
 
   NSTimeInterval targetTime = jsDuration - jsSchedulingOverhead;
   if (jsDuration < 0.018) { // Make sure short intervals run each frame