This is a testharness.js-based test.
Harness Error. harness_status.status = 1 , harness_status.message = 3 duplicate test names: "observer.root", "observer.thresholds", "observer.rootMargin"
PASS Observer attribute getters. 
PASS observer.root 
PASS observer.thresholds 
PASS observer.rootMargin 
PASS observer.root 
PASS observer.thresholds 
PASS observer.rootMargin 
Harness: the test ran to completion.