Added histogram for resize listener duration.

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

 /*
  * Copyright (C) 2006, 2007, 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 62 matching lines @@
 #include "core/loader/DocumentLoader.h"
 #include "core/loader/appcache/ApplicationCache.h"
 #include "core/page/ChromeClient.h"
 #include "core/page/CreateWindow.h"
 #include "core/page/Page.h"
 #include "core/page/WindowFeatures.h"
 #include "core/page/scrolling/ScrollingCoordinator.h"
 #include "core/timing/DOMWindowPerformance.h"
 #include "core/timing/Performance.h"
 #include "platform/EventDispatchForbiddenScope.h"
+#include "platform/Histogram.h"
 #include "platform/WebFrameScheduler.h"
 #include "platform/loader/fetch/ResourceFetcher.h"
 #include "platform/weborigin/SecurityOrigin.h"
 #include "platform/weborigin/Suborigin.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebScreenInfo.h"
 #include "public/platform/site_engagement.mojom-blink.h"
 
 #include <memory>
 
@@ skipping 1420 matching lines @@
   DCHECK(!EventDispatchForbiddenScope::isEventDispatchForbidden());
 #endif
 
   event->setTrusted(true);
   event->setTarget(target ? target : this);
   event->setCurrentTarget(this);
   event->setEventPhase(Event::kAtTarget);
 
   TRACE_EVENT1("devtools.timeline", "EventDispatch", "data",
                InspectorEventDispatchEvent::data(*event));
-  return fireEventListeners(event);
+  DispatchEventResult result;
+
+  if (frame() && frame()->isMainFrame() &&
+      event->type() == EventTypeNames::resize) {
+    SCOPED_BLINK_UMA_HISTOGRAM_TIMER("Blink.EventListenerDuration.Resize");
+    result = fireEventListeners(event);
+  } else {
+    result = fireEventListeners(event);
+  }
+
+  return result;
 }
 
 void LocalDOMWindow::removeAllEventListeners() {
   EventTarget::removeAllEventListeners();
 
   for (auto& it : m_eventListenerObservers) {
     it->didRemoveAllEventListeners(this);
   }
 
   if (frame() && frame()->host())
@@ skipping 108 matching lines @@
   DOMWindow::trace(visitor);
   Supplementable<LocalDOMWindow>::trace(visitor);
 }
 
 DEFINE_TRACE_WRAPPERS(LocalDOMWindow) {
   visitor->traceWrappers(m_customElements);
   DOMWindow::traceWrappers(visitor);
 }
 
 }  // namespace blink