Add UMA metrics for root scroller intervention to track forcing passive breakage.

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 28 matching lines @@
 #include "core/editing/Editor.h"
 #include "core/events/Event.h"
 #include "core/events/EventUtil.h"
 #include "core/frame/FrameHost.h"
 #include "core/frame/LocalDOMWindow.h"
 #include "core/frame/Settings.h"
 #include "core/frame/UseCounter.h"
 #include "core/inspector/ConsoleMessage.h"
 #include "core/inspector/InspectorInstrumentation.h"
 #include "platform/EventDispatchForbiddenScope.h"
+#include "platform/Histogram.h"
 #include "wtf/PtrUtil.h"
 #include "wtf/StdLibExtras.h"
 #include "wtf/Threading.h"
 #include "wtf/Vector.h"
 #include <memory>
 
 using namespace WTF;
 
 namespace blink {
 namespace {
 
+enum PassiveForcedListenerResultType {
+    PreventDefaultNotCalled,
+    DocumentLevelTouchPreventDefaultCalled,
+    PassiveForcedListenerResultTypeMax
+};
+
 Settings* windowSettings(LocalDOMWindow* executingWindow)
 {
     if (executingWindow) {
         if (LocalFrame* frame = executingWindow->frame()) {
             return frame->settings();
         }
     }
     return nullptr;
 }
 
@@ skipping 113 matching lines @@
     return nullptr;
 }
 
 inline LocalDOMWindow* EventTarget::executingWindow()
 {
     if (ExecutionContext* context = getExecutionContext())
         return context->executingWindow();
     return nullptr;
 }
 
-void EventTarget::setDefaultAddEventListenerOptions(const AtomicString& eventType, AddEventListenerOptions& options)
+void EventTarget::setDefaultAddEventListenerOptions(const AtomicString& eventType, AddEventListenerOptionsResolved& options)
 {
     if (!isScrollBlockingEvent(eventType)) {
         if (!options.hasPassive())
             options.setPassive(false);
         return;
     }
 
     if (LocalDOMWindow* executingWindow = this->executingWindow()) {
         if (options.hasPassive()) {
             UseCounter::count(executingWindow->document(), options.passive() ? UseCounter::AddEventListenerPassiveTrue : UseCounter::AddEventListenerPassiveFalse);
         }
     }
 
     if (RuntimeEnabledFeatures::passiveDocumentEventListenersEnabled() && isTouchScrollBlockingEvent(eventType)) {
         if (!options.hasPassive()) {
             if (Node* node = toNode()) {
                 if (node->isDocumentNode() || node->document().documentElement() == node || node->document().body() == node) {
                     options.setPassive(true);
+                    options.setPassiveForcedForDocumentTarget(true);
                     return;
                 }
             } else if (toLocalDOMWindow()) {
                 options.setPassive(true);
+                options.setPassiveForcedForDocumentTarget(true);
                 return;
             }
         }
     }
 
     if (Settings* settings = windowSettings(executingWindow())) {
         switch (settings->passiveListenerDefault()) {
         case PassiveListenerDefault::False:
             if (!options.hasPassive())
                 options.setPassive(false);
             break;
         case PassiveListenerDefault::True:
             if (!options.hasPassive())
                 options.setPassive(true);
             break;
         case PassiveListenerDefault::ForceAllTrue:
             options.setPassive(true);
             break;
         }
     } else {
         if (!options.hasPassive())
             options.setPassive(false);
     }
 }
 
 bool EventTarget::addEventListener(const AtomicString& eventType, EventListener* listener, bool useCapture)
 {
-    AddEventListenerOptions options;
+    AddEventListenerOptionsResolved options;
     options.setCapture(useCapture);
     setDefaultAddEventListenerOptions(eventType, options);
     return addEventListenerInternal(eventType, listener, options);
 }
 
 bool EventTarget::addEventListener(const AtomicString& eventType, EventListener* listener, const AddEventListenerOptionsOrBoolean& optionsUnion)
 {
     if (optionsUnion.isBoolean())
         return addEventListener(eventType, listener, optionsUnion.getAsBoolean());
     if (optionsUnion.isAddEventListenerOptions()) {
-        AddEventListenerOptions options = optionsUnion.getAsAddEventListenerOptions();
+        AddEventListenerOptionsResolved options = optionsUnion.getAsAddEventListenerOptions();
         return addEventListener(eventType, listener, options);
     }
     return addEventListener(eventType, listener);
 }
 
-bool EventTarget::addEventListener(const AtomicString& eventType, EventListener* listener, AddEventListenerOptions& options)
+bool EventTarget::addEventListener(const AtomicString& eventType, EventListener* listener, AddEventListenerOptionsResolved& options)
 {
     setDefaultAddEventListenerOptions(eventType, options);
     return addEventListenerInternal(eventType, listener, options);
 }
 
-bool EventTarget::addEventListenerInternal(const AtomicString& eventType, EventListener* listener, const AddEventListenerOptions& options)
+bool EventTarget::addEventListenerInternal(const AtomicString& eventType, EventListener* listener, const AddEventListenerOptionsResolved& options)
 {
     if (!listener)
         return false;
 
     V8DOMActivityLogger* activityLogger = V8DOMActivityLogger::currentActivityLoggerIfIsolatedWorld();
     if (activityLogger) {
         Vector<String> argv;
         argv.append(toNode() ? toNode()->nodeName() : interfaceName());
         argv.append(eventType);
         activityLogger->logEvent("blinkAddEventListener", argv.size(), argv.data());
@@ skipping 313 matching lines @@
             continue;
         if (event->eventPhase() == Event::BUBBLING_PHASE && registeredListener.capture())
             continue;
 
         // If stopImmediatePropagation has been called, we just break out immediately, without
         // handling any more events on this target.
         if (event->immediatePropagationStopped())
             break;
 
         event->setHandlingPassive(registeredListener.passive());
+        bool passiveForced = registeredListener.passiveForcedForDocumentTarget();
 
         InspectorInstrumentation::NativeBreakpoint nativeBreakpoint(context, this, event);
 
         EventListener* listener = registeredListener.listener();
 
         // To match Mozilla, the AT_TARGET phase fires both capturing and bubbling
         // event listeners, even though that violates some versions of the DOM spec.
         listener->handleEvent(context, event);
         firedListener = true;
 
         // If we're about to report this event listener as blocking, make sure it wasn't
         // removed while handling the event.
         if (shouldReportBlockedEvent && i > 0 && entry[i - 1].listener() == listener
             && !entry[i - 1].passive() && !entry[i - 1].blockedEventWarningEmitted() && !event->defaultPrevented()) {
             reportBlockedEvent(context, event, &entry[i - 1], now - event->platformTimeStamp());
         }
 
+        if (passiveForced) {
+            DEFINE_STATIC_LOCAL(EnumerationHistogram, passiveForcedHistogram, ("Event.PassiveForcedEventDispatchBreakage", PassiveForcedListenerResultTypeMax));

[tdresser, 2016/07/08 17:37:11]

How much work would it be to add a histogram test here?

[dtapuska, 2016/07/08 19:03:53]

Added :-)

+            PassiveForcedListenerResultType breakageType = PreventDefaultNotCalled;
+            if (event->preventDefaultCalledDuringPassive())
+                breakageType = DocumentLevelTouchPreventDefaultCalled;
+
+            passiveForcedHistogram.count(breakageType);
+        }
+
         event->setHandlingPassive(false);
 
         RELEASE_ASSERT(i <= size);
     }
     d->firingEventIterators->removeLast();
     return firedListener;
 }
 
 DispatchEventResult EventTarget::dispatchEventResult(const Event& event)
 {
@@ skipping 29 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