Refactored UseCounter code for event-listener-firing.

third_party/WebKit/Source/core/events/EventTarget.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  *           (C) 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ skipping 527 matching lines @@
     // TODO(dtapuska): Should we really do counting here for these events
     // if we really didn't fire a listener? For example having a bubbling
     // listener on an event that doesn't bubble likely records a UMA
     // metric where it probably shouldn't because it was never fired.
     // See https://crbug.com/612829
     Editor::countEvent(getExecutionContext(), event);
     countLegacyEvents(legacyTypeName, listenersVector, legacyListenersVector);
     return dispatchEventResult(*event);
 }
 
+bool EventTarget::checkTypeThenUseCount(
+    const Event* event, const AtomicString& eventTypeToCount, const UseCounter::Feature feature)
+{
+    if (event->type() == eventTypeToCount) {
+        if (LocalDOMWindow* executingWindow = this->executingWindow())
+            UseCounter::count(executingWindow->document(), feature);
+        return true;
+    }
+    return false;
+}
+
 bool EventTarget::fireEventListeners(Event* event, EventTargetData* d, EventListenerVector& entry)
 {
     // Fire all listeners registered for this event. Don't fire listeners removed
     // during event dispatch. Also, don't fire event listeners added during event
     // dispatch. Conveniently, all new event listeners will be added after or at
     // index |size|, so iterating up to (but not including) |size| naturally excludes
     // new event listeners.
-    //
-    // TODO(mustaq): This code needs to be refactored, crbug.com/629601
 
-    if (event->type() == EventTypeNames::beforeunload) {
+    if (checkTypeThenUseCount(event, EventTypeNames::beforeunload, UseCounter::DocumentBeforeUnloadFired)) {
         if (LocalDOMWindow* executingWindow = this->executingWindow()) {
             if (executingWindow->top())

[bokan, 2016/08/05 15:34:25]

I know you didn't add this but I think this is wrong - all frames will count as
subframes here. It should be `if (executingWindow != executingWindow->top())`.
It looks like this was accidentally changed in
https://chromiumcodereview.appspot.com/22564003. +ojan@ to confirm/FYI since he
added it.

                 UseCounter::count(executingWindow->document(), UseCounter::SubFrameBeforeUnloadFired);
-            UseCounter::count(executingWindow->document(), UseCounter::DocumentBeforeUnloadFired);
         }
-    } else if (event->type() == EventTypeNames::unload) {
-        if (LocalDOMWindow* executingWindow = this->executingWindow())
-            UseCounter::count(executingWindow->document(), UseCounter::DocumentUnloadFired);
-    } else if (event->type() == EventTypeNames::DOMFocusIn || event->type() == EventTypeNames::DOMFocusOut) {
-        if (LocalDOMWindow* executingWindow = this->executingWindow())
-            UseCounter::count(executingWindow->document(), UseCounter::DOMFocusInOutEvent);
-    } else if (event->type() == EventTypeNames::focusin || event->type() == EventTypeNames::focusout) {
-        if (LocalDOMWindow* executingWindow = this->executingWindow())
-            UseCounter::count(executingWindow->document(), UseCounter::FocusInOutEvent);
-    } else if (event->type() == EventTypeNames::textInput) {
-        if (LocalDOMWindow* executingWindow = this->executingWindow())
-            UseCounter::count(executingWindow->document(), UseCounter::TextInputFired);
-    } else if (event->type() == EventTypeNames::touchstart) {
-        if (LocalDOMWindow* executingWindow = this->executingWindow())
-            UseCounter::count(executingWindow->document(), UseCounter::TouchStartFired);
-    } else if (event->type() == EventTypeNames::mousedown) {
-        if (LocalDOMWindow* executingWindow = this->executingWindow())
-            UseCounter::count(executingWindow->document(), UseCounter::MouseDownFired);
-    } else if (event->type() == EventTypeNames::pointerdown) {
+    } else if (checkTypeThenUseCount(event, EventTypeNames::unload, UseCounter::DocumentUnloadFired)) {
+    } else if (checkTypeThenUseCount(event, EventTypeNames::DOMFocusIn, UseCounter::DOMFocusInOutEvent)) {
+    } else if (checkTypeThenUseCount(event, EventTypeNames::DOMFocusOut, UseCounter::DOMFocusInOutEvent)) {
+    } else if (checkTypeThenUseCount(event, EventTypeNames::focusin, UseCounter::FocusInOutEvent)) {
+    } else if (checkTypeThenUseCount(event, EventTypeNames::focusout, UseCounter::FocusInOutEvent)) {
+    } else if (checkTypeThenUseCount(event, EventTypeNames::textInput, UseCounter::TextInputFired)) {
+    } else if (checkTypeThenUseCount(event, EventTypeNames::touchstart, UseCounter::TouchStartFired)) {
+    } else if (checkTypeThenUseCount(event, EventTypeNames::mousedown, UseCounter::MouseDownFired)) {
+    } else if (checkTypeThenUseCount(event, EventTypeNames::pointerdown, UseCounter::PointerDownFired)) {
         if (LocalDOMWindow* executingWindow = this->executingWindow()) {
-            if (event->isPointerEvent() && static_cast<PointerEvent*>(event)->pointerType() == "touch")
+            if (static_cast<PointerEvent*>(event)->pointerType() == "touch")
                 UseCounter::count(executingWindow->document(), UseCounter::PointerDownFiredForTouch);
-            UseCounter::count(executingWindow->document(), UseCounter::PointerDownFired);
         }
     }
 
     ExecutionContext* context = getExecutionContext();
     if (!context)
         return false;
 
     size_t i = 0;
     size_t size = entry.size();
     if (!d->firingEventIterators)
@@ skipping 97 matching lines @@
     // they have one less listener to invoke.
     if (d->firingEventIterators) {
         for (size_t i = 0; i < d->firingEventIterators->size(); ++i) {
             d->firingEventIterators->at(i).iterator = 0;
             d->firingEventIterators->at(i).end = 0;
         }
     }
 }
 
 } // namespace blink