Migrate WTF::HashSet::add() to ::insert() [part 1 of N]

third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp

Index: third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp
diff --git a/third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp b/third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp
index d95e24c5fc742080577bb2f240655be7cb40cbf7..da76ba78d623c0e4eed0bfba26b55273909777ca 100644
--- a/third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp
+++ b/third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp
@@ -485,7 +485,7 @@ void LocalDOMWindow::frameDestroyed() {
 
 void LocalDOMWindow::registerEventListenerObserver(
     EventListenerObserver* eventListenerObserver) {
-  m_eventListenerObservers.add(eventListenerObserver);
+  m_eventListenerObservers.insert(eventListenerObserver);
 }
 
 void LocalDOMWindow::reset() {
@@ -623,7 +623,7 @@ void LocalDOMWindow::schedulePostMessage(MessageEvent* event,
                            UserGestureIndicator::currentToken());
   timer->startOneShot(0, BLINK_FROM_HERE);
   timer->suspendIfNeeded();
-  m_postMessageTimers.add(timer);
+  m_postMessageTimers.insert(timer);
 }
 
 void LocalDOMWindow::postMessageTimerFired(PostMessageTimer* timer) {