Remove the blocking touch handlers for the input[type=range] and add touch-action instead

third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 1427 matching lines @@
     const String& name = toCSSCustomIdentValue(value).value();
     const StylePropertySet* propertySet = state.customPropertySetForApplyAtRule(name);
     if (propertySet)
         applyProperties<priority>(state, propertySet, isImportant, inheritedOnly, propertyWhitelistType);
 }
 
 template <CSSPropertyPriority priority>
 void StyleResolver::applyProperties(StyleResolverState& state, const StylePropertySet* properties, bool isImportant, bool inheritedOnly, PropertyWhitelistType propertyWhitelistType)
 {
     unsigned propertyCount = properties->propertyCount();
+    bool hasTouchAction = false;
     for (unsigned i = 0; i < propertyCount; ++i) {
         StylePropertySet::PropertyReference current = properties->propertyAt(i);
         CSSPropertyID property = current.id();
 
         if (property == CSSPropertyApplyAtRule) {
             applyPropertiesForApplyAtRule<priority>(state, current.value(), isImportant, inheritedOnly, propertyWhitelistType);
             continue;
         }
 
         if (isImportant != current.isImportant())
@@ skipping 11 matching lines @@
             // If the property value is explicitly inherited, we need to apply further non-inherited properties
             // as they might override the value inherited here. For this reason we don't allow declarations with
             // explicitly inherited properties to be cached.
             DCHECK(!current.value().isInheritedValue());
             continue;
         }
 
         if (!CSSPropertyPriorityData<priority>::propertyHasPriority(property))
             continue;
 
+        if (property == CSSPropertyTouchAction) {
+            hasTouchAction = true;
+        }
+
         StyleBuilder::applyProperty(current.id(), state, current.value());
+
+        if (property == CSSPropertyWebkitAppearance && !hasTouchAction) {

[tkent, 2016/08/09 00:29:46]

This code looks like the state.style() will have touch-action:pan-* even if the
element is not <input type=range>.

We have appearance-specific style adjustment code in LayoutTheme::adjustStyle().
We can check <input type=range> inside it.
Also, we have some other slider appearances; MediaFullScreenVolumeSliderPart,
MediaSliderPart, and MediaVolumeSliderPart.

+            if (state.style()->appearance() == SliderVerticalPart) {
+                state.style()->setTouchAction(TouchActionPanX);
+            }
+            if (state.style()->appearance() == SliderHorizontalPart) {
+                state.style()->setTouchAction(TouchActionPanY);
+            }
+        }
     }
 }
 
 template <CSSPropertyPriority priority>
 void StyleResolver::applyMatchedProperties(StyleResolverState& state, const MatchedPropertiesRange& range, bool isImportant, bool inheritedOnly)
 {
     if (range.isEmpty())
         return;
 
     if (state.style()->insideLink() != NotInsideLink) {
@@ skipping 253 matching lines @@
     visitor->trace(m_siblingRuleSet);
     visitor->trace(m_uncommonAttributeRuleSet);
     visitor->trace(m_watchedSelectorsRules);
     visitor->trace(m_treeBoundaryCrossingScopes);
     visitor->trace(m_styleSharingLists);
     visitor->trace(m_pendingStyleSheets);
     visitor->trace(m_document);
 }
 
 } // namespace blink