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

third_party/WebKit/Source/core/html/forms/RangeInputType.cpp

Index: third_party/WebKit/Source/core/html/forms/RangeInputType.cpp
diff --git a/third_party/WebKit/Source/core/html/forms/RangeInputType.cpp b/third_party/WebKit/Source/core/html/forms/RangeInputType.cpp
index e91b6744e21b01b7d9fde5abab14d158326bc22a..c968e7573600d2148c231ca626758d4aa2c80c8d 100644
--- a/third_party/WebKit/Source/core/html/forms/RangeInputType.cpp
+++ b/third_party/WebKit/Source/core/html/forms/RangeInputType.cpp
@@ -186,9 +186,9 @@ void RangeInputType::handleTouchEvent(TouchEvent* event)
     }
 }
 
-bool RangeInputType::hasTouchEventHandler() const
+TouchHandlerType RangeInputType::touchEventHandlerType() const
 {
-    return true;
+    return Passive;
 }
 
 void RangeInputType::handleKeydownEvent(KeyboardEvent* event)
@@ -259,6 +259,16 @@ void RangeInputType::createShadowSubtree()
     HTMLDivElement* track = HTMLDivElement::create(document);
     track->setShadowPseudoId(AtomicString("-webkit-slider-runnable-track"));
     track->setAttribute(idAttr, ShadowElementNames::sliderTrack());
+    bool isVertical = false;
+    if (element().layoutObject()) {
+        ControlPart part = element().layoutObject()->style()->appearance();
+        isVertical = part == SliderVerticalPart;
+    }
+    if (isVertical) {
+        track->setAttribute(styleAttr, "touch-action:pan-x");
+    } else {
+        track->setAttribute(styleAttr, "touch-action:pan-y");
+    }

[majidvp, 2016/08/04 21:21:58]

This logic looks reasonable but I think this does not handle style updates 
correctly. For example if I open devtools and change -webkit-appearance
value we don't recreate the shadow tree but only re-layout and re-paint it.

So I think this should actually move inside |LayotuSliderContainer::layout()|
which is invoked anytime style change invalidates paint, layout.

     track->appendChild(SliderThumbElement::create(document));
     HTMLElement* container = SliderContainerElement::create(document);
     container->appendChild(track);