Communicate whether passive event listeners exist to cc.

third_party/WebKit/Source/core/layout/LayoutObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 2022 matching lines @@
         if (diff.needsLayout()) {
             setFloating(false);
             clearPositionedState();
         }
     } else {
         s_affectsParentBlock = false;
     }
 
     // Elements with non-auto touch-action will send a SetTouchAction message
     // on touchstart in EventHandler::handleTouchEvent, and so effectively have
     // a touchstart handler that must be reported.

[Rick Byers, 2016/02/04 22:18:57]

nit: add a TODO to remove this blocking touch handler - reference
http://crbug.com/318381

     //
     // Since a CSS property cannot be applied directly to a text node, a
     // handler will have already been added for its parent so ignore it.
     TouchAction oldTouchAction = m_style ? m_style->touchAction() : TouchActionAuto;
     if (node() && !node()->isTextNode() && (oldTouchAction == TouchActionAuto) != (newStyle.touchAction() == TouchActionAuto)) {
         EventHandlerRegistry& registry = document().frameHost()->eventHandlerRegistry();
         if (newStyle.touchAction() != TouchActionAuto)
-            registry.didAddEventHandler(*node(), EventHandlerRegistry::TouchEvent);
+            registry.didAddEventHandler(*node(), EventHandlerRegistry::TouchEventBlocking);
         else
-            registry.didRemoveEventHandler(*node(), EventHandlerRegistry::TouchEvent);
+            registry.didRemoveEventHandler(*node(), EventHandlerRegistry::TouchEventBlocking);
     }
 }
 
 static bool areNonIdenticalCursorListsEqual(const ComputedStyle* a, const ComputedStyle* b)
 {
     ASSERT(a->cursors() != b->cursors());
     return a->cursors() && b->cursors() && *a->cursors() == *b->cursors();
 }
 
 static inline bool areCursorsEqual(const ComputedStyle* a, const ComputedStyle* b)
@@ skipping 501 matching lines @@
 
     if (hasCounterNodeMap())
         LayoutCounter::destroyCounterNodes(*this);
 
     // Remove the handler if node had touch-action set. Handlers are not added
     // for text nodes so don't try removing for one too. Need to check if
     // m_style is null in cases of partial construction. Any handler we added
     // previously may have already been removed by the Document independently.
     if (node() && !node()->isTextNode() && m_style && m_style->touchAction() != TouchActionAuto) {
         EventHandlerRegistry& registry = document().frameHost()->eventHandlerRegistry();
-        if (registry.eventHandlerTargets(EventHandlerRegistry::TouchEvent)->contains(node()))
-            registry.didRemoveEventHandler(*node(), EventHandlerRegistry::TouchEvent);
+        if (registry.eventHandlerTargets(EventHandlerRegistry::TouchEventBlocking)->contains(node()))
+            registry.didRemoveEventHandler(*node(), EventHandlerRegistry::TouchEventBlocking);
     }
 
     setAncestorLineBoxDirty(false);
 
     if (selectionPaintInvalidationMap)
         selectionPaintInvalidationMap->remove(this);
 
     if (RuntimeEnabledFeatures::slimmingPaintV2Enabled())
         clearObjectPaintProperties();
 
@@ skipping 981 matching lines @@
         const blink::LayoutObject* root = object1;
         while (root->parent())
             root = root->parent();
         root->showLayoutTreeAndMark(object1, "*", object2, "-", 0);
     } else {
         fprintf(stderr, "Cannot showLayoutTree. Root is (nil)\n");
     }
 }
 
 #endif