Add iterator support to blink::EventPath.

third_party/WebKit/Source/core/events/EventPath.h

Index: third_party/WebKit/Source/core/events/EventPath.h
diff --git a/third_party/WebKit/Source/core/events/EventPath.h b/third_party/WebKit/Source/core/events/EventPath.h
index 544c77f7a85d51ac9c7eb4344d5a9c294f36c1a7..8aafe26e7c18ecbd5764c647d4ae32bcc77d40ba 100644
--- a/third_party/WebKit/Source/core/events/EventPath.h
+++ b/third_party/WebKit/Source/core/events/EventPath.h
@@ -52,6 +52,12 @@ class CORE_EXPORT EventPath final : public GarbageCollected<EventPath> {
 
   void initializeWith(Node&, Event*);
 
+  const HeapVector<NodeEventContext>& nodeEventContexts() const {
+    return m_nodeEventContexts;
+  }
+  HeapVector<NodeEventContext>& nodeEventContexts() {
+    return m_nodeEventContexts;
+  }
   NodeEventContext& operator[](size_t index) {
     return m_nodeEventContexts[index];
   }