[MERGE 2704] IntersectionObserver: check for constructed Frame.

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

Index: third_party/WebKit/Source/core/dom/IntersectionObserver.cpp
diff --git a/third_party/WebKit/Source/core/dom/IntersectionObserver.cpp b/third_party/WebKit/Source/core/dom/IntersectionObserver.cpp
index b0b42f34f122259d9f5fc04d6fc616a3a6ff49ec..dfab75ba4455b8a2123dc93e6dde922f8d0798ae 100644
--- a/third_party/WebKit/Source/core/dom/IntersectionObserver.cpp
+++ b/third_party/WebKit/Source/core/dom/IntersectionObserver.cpp
@@ -177,7 +177,11 @@ void IntersectionObserver::observe(Element* target)
     if (target->ensureIntersectionObserverData().getObservationFor(*this))
         return;
 
-    bool shouldReportRootBounds = target->document().frame()->securityContext()->getSecurityOrigin()->canAccess(rootNode()->document().frame()->securityContext()->getSecurityOrigin());
+    bool shouldReportRootBounds = false;
+    LocalFrame* targetFrame = target->document().frame();
+    LocalFrame* rootFrame = rootNode()->document().frame();
+    if (targetFrame && rootFrame)
+        shouldReportRootBounds = targetFrame->securityContext()->getSecurityOrigin()->canAccess(rootFrame->securityContext()->getSecurityOrigin());
     IntersectionObservation* observation = new IntersectionObservation(*this, *target, shouldReportRootBounds);
     target->ensureIntersectionObserverData().addObservation(*observation);
     m_observations.add(observation);