Remove UserGesture on touch scrolls

third_party/WebKit/Source/core/input/PointerEventManager.cpp

Index: third_party/WebKit/Source/core/input/PointerEventManager.cpp
diff --git a/third_party/WebKit/Source/core/input/PointerEventManager.cpp b/third_party/WebKit/Source/core/input/PointerEventManager.cpp
index f3b1dd0d0c524ebcbd722ae74953040dbedbd00b..aa42f46837b4e09bc0c4b25bce46f0f942d3b23f 100644
--- a/third_party/WebKit/Source/core/input/PointerEventManager.cpp
+++ b/third_party/WebKit/Source/core/input/PointerEventManager.cpp
@@ -169,14 +169,6 @@ WebInputEventResult PointerEventManager::dispatchPointerEvent(
       UseCounter::count(m_frame->document(),
                         UseCounter::PointerEventDispatchPointerDown);
 
-    std::unique_ptr<UserGestureIndicator> gestureIndicator;
-    if (eventType == EventTypeNames::pointerup &&
-        pointerEvent->pointerType() == "touch") {
-      gestureIndicator =
-          wrapUnique(new UserGestureIndicator(DocumentUserGestureToken::create(
-              target->toNode() ? &target->toNode()->document() : nullptr)));
-    }
-
     DispatchEventResult dispatchResult = target->dispatchEvent(pointerEvent);
     return EventHandlingUtil::toWebInputEventResult(dispatchResult);
   }
@@ -298,7 +290,6 @@ WebInputEventResult PointerEventManager::handleTouchEvents(
     const PlatformTouchEvent& event) {
   if (event.type() == PlatformEvent::TouchScrollStarted) {
     blockTouchPointers();
-    m_touchEventManager->setTouchScrollStarted();
     return WebInputEventResult::HandledSystem;
   }
 
@@ -311,18 +302,36 @@ WebInputEventResult PointerEventManager::handleTouchEvents(
   }
   if (newTouchSequence)
     unblockTouchPointers();
+
+  // Do any necessary hit-tests and compute the event targets for all pointers
+  // in the event.
   HeapVector<TouchEventManager::TouchInfo> touchInfos;
+  computeTouchTargets(event, touchInfos);
+
+  // Any finger lifting is a user gesture only when it wasn't associated with a
+  // scroll.
+  // https://docs.google.com/document/d/1oF1T3O7_E4t1PYHV6gyCwHxOi3ystm0eSL5xZu7nvOg/edit#
+  // Re-use the same UserGesture for touchend and pointerup (but not for the
+  // mouse events generated by GestureTap).
+  // For the rare case of multi-finger scenarios spanning documents, it
+  // seems extremely unlikely to matter which document the gesture is
+  // associated with so just pick the first finger.
+  RefPtr<UserGestureToken> possibleGestureToken;
+  if (event.type() == PlatformEvent::TouchEnd &&
+      !m_inCanceledStateForPointerTypeTouch) {
+    possibleGestureToken =
+        DocumentUserGestureToken::create(touchInfos[0].targetFrame->document());
+  }
+  UserGestureIndicator holder(possibleGestureToken);
 
   dispatchTouchPointerEvents(event, touchInfos);
 
   return m_touchEventManager->handleTouchEvent(event, touchInfos);
 }
 
-void PointerEventManager::dispatchTouchPointerEvents(
+void PointerEventManager::computeTouchTargets(
     const PlatformTouchEvent& event,
     HeapVector<TouchEventManager::TouchInfo>& touchInfos) {
-  // Iterate through the touch points, sending PointerEvents to the targets as
-  // required.
   for (const auto& touchPoint : event.touchPoints()) {
     TouchEventManager::TouchInfo touchInfo;
     touchInfo.point = touchPoint;
@@ -373,6 +382,17 @@ void PointerEventManager::dispatchTouchPointerEvents(
       touchInfo.targetFrame = touchInfo.touchNode->document().frame();
     }
 
+    touchInfos.append(touchInfo);
+  }
+}
+
+void PointerEventManager::dispatchTouchPointerEvents(
+    const PlatformTouchEvent& event,
+    HeapVector<TouchEventManager::TouchInfo>& touchInfos) {
+  // Iterate through the touch points, sending PointerEvents to the targets as
+  // required.
+  for (auto touchInfo : touchInfos) {
+    const PlatformTouchPoint& touchPoint = touchInfo.point;
     // Do not send pointer events for stationary touches or null targetFrame
     if (touchInfo.touchNode && touchInfo.targetFrame &&
         touchPoint.state() != PlatformTouchPoint::TouchStationary &&
@@ -405,8 +425,6 @@ void PointerEventManager::dispatchTouchPointerEvents(
         m_touchIdsForCanceledPointerdowns.append(event.uniqueTouchEventId());
       }
     }
-
-    touchInfos.append(touchInfo);
   }
 }