Remove unnecessary RAF from tests.

third_party/WebKit/Source/core/dom/IntersectionObserverController.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/dom/IntersectionObserverController.h"
 
 #include "core/dom/Document.h"
 
 namespace blink {
 
 typedef HeapVector<Member<IntersectionObserver>> IntersectionObserverVector;
 
 IntersectionObserverController::IntersectionObserverController()
     : m_timer(this, &IntersectionObserverController::deliverIntersectionObservations)
 {
 }
 
 IntersectionObserverController::~IntersectionObserverController() { }
 
 void IntersectionObserverController::scheduleIntersectionObserverForDelivery(IntersectionObserver& observer)
 {
-    // TODO(szager): use idle callback with a timeout
+    // TODO(szager): use idle callback with a timeout.  Until we do that, there is no
+    // reliable way to write a test for takeRecords, because it's impossible to guarantee
+    // that javascript will get a chance to run before the timer fires.

[ojan, 2016/01/12 00:43:05]

As per in person discussion, not quite clear if this is true. I *think* if you
setTimeout(0) inside of rAF, then the timer started on line 26 will fire after
the setTimeout(0).

     if (!m_timer.isActive())
         m_timer.startOneShot(0, BLINK_FROM_HERE);
     m_pendingIntersectionObservers.add(&observer);
 }
 
 void IntersectionObserverController::deliverIntersectionObservations(Timer<IntersectionObserverController>*)
 {
     IntersectionObserverVector observers;
     copyToVector(m_pendingIntersectionObservers, observers);
     m_pendingIntersectionObservers.clear();
@@ skipping 25 matching lines @@
     m_trackedIntersectionObservers.removeAll(toRemove);
 }
 
 DEFINE_TRACE(IntersectionObserverController)
 {
     visitor->trace(m_trackedIntersectionObservers);
     visitor->trace(m_pendingIntersectionObservers);
 }
 
 } // namespace blink