Migrate WTF::Vector::append() to ::push_back() [part 4 of N]

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"
 #include "core/dom/Element.h"
 #include "core/dom/TaskRunnerHelper.h"
 #include "platform/tracing/TraceEvent.h"
@@ skipping 74 matching lines @@
 void IntersectionObserverController::addTrackedObserver(
     IntersectionObserver& observer) {
   m_trackedIntersectionObservers.add(&observer);
 }
 
 void IntersectionObserverController::removeTrackedObserversForRoot(
     const Node& root) {
   HeapVector<Member<IntersectionObserver>> toRemove;
   for (auto& observer : m_trackedIntersectionObservers) {
     if (observer->root() == &root)
-      toRemove.append(observer);
+      toRemove.push_back(observer);
   }
   m_trackedIntersectionObservers.removeAll(toRemove);
 }
 
 DEFINE_TRACE(IntersectionObserverController) {
   visitor->trace(m_trackedIntersectionObservers);
   visitor->trace(m_pendingIntersectionObservers);
   SuspendableObject::trace(visitor);
 }
 
 }  // namespace blink