mozilla-central: changeset 343102:2f5ea49d65cf21e1ecf7c7c6c348abd3b9d2a456

author	Olli Pettay <Olli.Pettay@helsinki.fi>
	Wed, 15 Feb 2017 17:04:16 +0200
changeset 343102	2f5ea49d65cf21e1ecf7c7c6c348abd3b9d2a456
parent 343101	8f45618754feef3ba059cf47a5d7b8ed437113a5
child 343103	3cac14211742ccb4b1f98fc4e44236eeb0d7c27e
push id	31369
push user	kwierso@gmail.com
push date	Thu, 16 Feb 2017 00:18:40 +0000
treeherder	mozilla-central@e9b926463f9e [default view] [failures only]
perfherder	[talos] [build metrics] [platform microbench] (compared to previous push)
reviewers	tschneider
bugs	1338886
milestone	54.0a1
first release with	nightly linux32 a9ec72f82299 / 54.0a1 / 20170216110247 / files nightly linux64 a9ec72f82299 / 54.0a1 / 20170216110247 / files nightly mac a9ec72f82299 / 54.0a1 / 20170216030210 / files nightly win32 a9ec72f82299 / 54.0a1 / 20170216030210 / files nightly win64 a9ec72f82299 / 54.0a1 / 20170216030210 / files
last release without	nightly linux32 0a7831d838f7 / 54.0a1 / 20170215110151 / files nightly linux64 0a7831d838f7 / 54.0a1 / 20170215110151 / files nightly mac 0a7831d838f7 / 54.0a1 / 20170215030342 / files nightly win32 0a7831d838f7 / 54.0a1 / 20170215030342 / files nightly win64 0a7831d838f7 / 54.0a1 / 20170215030342 / files

--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -12610,16 +12610,20 @@ void
 nsDocument::RemoveIntersectionObserver(DOMIntersectionObserver* aObserver)
 {
   mIntersectionObservers.RemoveElement(aObserver);
 }
 
 void
 nsDocument::UpdateIntersectionObservations()
 {
+  if (mIntersectionObservers.IsEmpty()) {
+    return;
+  }
+
   DOMHighResTimeStamp time = 0;
   if (nsPIDOMWindowInner* window = GetInnerWindow()) {
     Performance* perf = window->GetPerformance();
     if (perf) {
       time = perf->Now();
     }
   }
   for (const auto& observer : mIntersectionObservers) {