Remove setting cancelBubble to false.

According to spec https://dom.spec.whatwg.org/#dom-event-cancelbubble, setting
cancelBubble to true is considered as an alias to stopPropagation(), setting
cancelBubble to false is a no-op. Detail discussion is on
whatwg/dom#211.

BUG=675549

Review-Url: https://codereview.chromium.org/2641953006
Cr-Commit-Position: refs/heads/master@{#446118}

Author: lpy

third_party/WebKit/LayoutTests/external/wpt/dom/events/Event-cancelBubble-expected.txt

@@ -87,7 +87,6 @@ Event::Event(const AtomicString& eventType,
       m_immediatePropagationStopped(false),
       m_defaultPrevented(false),
       m_defaultHandled(false),
-      m_cancelBubble(false),
       m_wasInitialized(true),
       m_isTrusted(false),
       m_preventDefaultCalledOnUncancelableEvent(false),
@@ -337,11 +336,8 @@ double Event::timeStamp(ScriptState* scriptState) const {
 }
 
 void Event::setCancelBubble(ExecutionContext* context, bool cancel) {
-  if (!m_cancelBubble && cancel)
-    UseCounter::count(context, UseCounter::EventCancelBubbleWasChangedToTrue);
-  else if (m_cancelBubble && !cancel)
-    UseCounter::count(context, UseCounter::EventCancelBubbleWasChangedToFalse);
-  m_cancelBubble = cancel;
+  if (cancel)
+    m_propagationStopped = true;
 }
 
 DEFINE_TRACE(Event) {

third_party/WebKit/LayoutTests/external/wpt/dom/events/Event-dispatch-bubble-canceled-expected.txt

@@ -199,7 +199,7 @@ class CORE_EXPORT Event : public GarbageCollectedFinalized<Event>,
   void setDefaultHandled() { m_defaultHandled = true; }
 
   bool cancelBubble(ExecutionContext* = nullptr) const {
-    return m_cancelBubble;
+    return propagationStopped();
   }
   void setCancelBubble(ExecutionContext*, bool);
 
@@ -285,7 +285,6 @@ class CORE_EXPORT Event : public GarbageCollectedFinalized<Event>,
   unsigned m_immediatePropagationStopped : 1;
   unsigned m_defaultPrevented : 1;
   unsigned m_defaultHandled : 1;
-  unsigned m_cancelBubble : 1;
   unsigned m_wasInitialized : 1;
   unsigned m_isTrusted : 1;
 

third_party/WebKit/LayoutTests/external/wpt/dom/events/Event-dispatch-multiple-cancelBubble-expected.txt

@@ -218,11 +218,6 @@ inline void EventDispatcher::dispatchEventAtBubbling() {
     } else if (m_event->bubbles() && !m_event->cancelBubble()) {
       m_event->setEventPhase(Event::kBubblingPhase);
     } else {
-      if (m_event->bubbles() && m_event->cancelBubble() &&
-          eventContext.node() &&
-          eventContext.node()->hasEventListeners(m_event->type()))
-        UseCounter::count(eventContext.node()->document(),
-                          UseCounter::EventCancelBubbleAffected);
       continue;
     }
     eventContext.handleLocalEvents(*m_event);
@@ -232,17 +227,6 @@ inline void EventDispatcher::dispatchEventAtBubbling() {
   if (m_event->bubbles() && !m_event->cancelBubble()) {
     m_event->setEventPhase(Event::kBubblingPhase);
     m_event->eventPath().windowEventContext().handleLocalEvents(*m_event);
-  } else if (m_event->bubbles() &&
-             m_event->eventPath().windowEventContext().window() &&
-             m_event->eventPath()
-                 .windowEventContext()
-                 .window()
-                 ->hasEventListeners(m_event->type())) {
-    UseCounter::count(m_event->eventPath()
-                          .windowEventContext()
-                          .window()
-                          ->getExecutionContext(),
-                      UseCounter::EventCancelBubbleAffected);
   }
 }
 

third_party/WebKit/LayoutTests/external/wpt/dom/events/Event-propagation-expected.txt

@@ -1019,9 +1019,6 @@ class CORE_EXPORT UseCounter {
     ProgressElementWithNoneAppearance = 1345,
     ProgressElementWithProgressBarAppearance = 1346,
     PointerEventAddListenerCount = 1347,
-    EventCancelBubbleAffected = 1348,
-    EventCancelBubbleWasChangedToTrue = 1349,
-    EventCancelBubbleWasChangedToFalse = 1350,
     CSSValueAppearanceNone = 1351,
     CSSValueAppearanceNotNone = 1352,
     CSSValueAppearanceOthers = 1353,

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

@@ -28,7 +28,6 @@
 
 #include "modules/indexeddb/IDBEventDispatcher.h"
 
-#include "core/frame/UseCounter.h"
 #include "modules/EventModules.h"
 #include "modules/EventTargetModules.h"
 
@@ -51,31 +50,15 @@ DispatchEventResult IDBEventDispatcher::dispatch(
   event->setEventPhase(Event::kAtTarget);
   event->setCurrentTarget(eventTargets[0].get());
   eventTargets[0]->fireEventListeners(event);
-  if (event->propagationStopped() || !event->bubbles())
+  if (event->propagationStopped() || !event->bubbles() || event->cancelBubble())
     goto doneDispatching;
-  if (event->bubbles() && event->cancelBubble()) {
-    for (size_t i = 1; i < size; ++i) {  // Don't do the first element.
-      if (eventTargets[i]->hasEventListeners(event->type()))
-        UseCounter::count(eventTargets[i]->getExecutionContext(),
-                          UseCounter::EventCancelBubbleAffected);
-    }
-    goto doneDispatching;
-  }
 
   event->setEventPhase(Event::kBubblingPhase);
   for (size_t i = 1; i < size; ++i) {  // Don't do the first element.
     event->setCurrentTarget(eventTargets[i].get());
     eventTargets[i]->fireEventListeners(event);
-    if (event->propagationStopped())
-      goto doneDispatching;
-    if (event->cancelBubble()) {
-      for (size_t j = i + 1; j < size; ++j) {
-        if (eventTargets[j]->hasEventListeners(event->type()))
-          UseCounter::count(eventTargets[j]->getExecutionContext(),
-                            UseCounter::EventCancelBubbleAffected);
-      }
+    if (event->propagationStopped() || event->cancelBubble())
       goto doneDispatching;
-    }
   }
 
 doneDispatching:

third_party/WebKit/Source/core/events/Event.h

@@ -89635,9 +89635,6 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="1345" label="ProgressElementWithNoneAppearance"/>
   <int value="1346" label="ProgressElementWithProgressBarAppearance"/>
   <int value="1347" label="PointerEventAddListenerCount"/>
-  <int value="1348" label="EventCancelBubbleAffected"/>
-  <int value="1349" label="EventCancelBubbleWasChangedToTrue"/>
-  <int value="1350" label="EventCancelBubbleWasChangedToFalse"/>
   <int value="1351" label="CSSValueAppearanceNone"/>
   <int value="1352" label="CSSValueAppearanceNotNone"/>
   <int value="1353" label="CSSValueAppearanceOthers"/>