Notify Blink about start of gesture scroll through a queued event.

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

Index: third_party/WebKit/Source/core/events/PointerEventFactory.cpp
diff --git a/third_party/WebKit/Source/core/events/PointerEventFactory.cpp b/third_party/WebKit/Source/core/events/PointerEventFactory.cpp
index 3c7ef36f4a75d2f1884e87c3a45fcf1e28d8c824..42958999d4c4bdc29562f5b442b3f57a406f7463 100644
--- a/third_party/WebKit/Source/core/events/PointerEventFactory.cpp
+++ b/third_party/WebKit/Source/core/events/PointerEventFactory.cpp
@@ -166,13 +166,13 @@ PassRefPtrWillBeRawPtr<PointerEvent> PointerEventFactory::create(const AtomicStr
     return PointerEvent::create(type, pointerEventInit);
 }
 
-
-PassRefPtrWillBeRawPtr<PointerEvent> PointerEventFactory::createPointerCancel(const PlatformTouchPoint& touchPoint)
+PassRefPtrWillBeRawPtr<PointerEvent> PointerEventFactory::createPointerCancel(const int pointerId, const WebPointerProperties::PointerType pointerType)
 {
     PointerEventInit pointerEventInit;
 
-    setIdTypeButtons(pointerEventInit, touchPoint.pointerProperties(), 0);
-
+    pointerEventInit.setPointerId(pointerId);
+    pointerEventInit.setPointerType(pointerTypeNameForWebPointPointerType(pointerType));
+    pointerEventInit.setIsPrimary(isPrimary(pointerId));
     pointerEventInit.setBubbles(true);
     pointerEventInit.setCancelable(false);
 
@@ -267,10 +267,8 @@ int PointerEventFactory::addIdAndActiveButtons(const IncomingId p,
     return mappedId;
 }
 
-bool PointerEventFactory::remove(
-    const PassRefPtrWillBeRawPtr<PointerEvent> pointerEvent)
+bool PointerEventFactory::remove(const int mappedId)
 {
-    int mappedId = pointerEvent->pointerId();
     // Do not remove mouse pointer id as it should always be there
     if (mappedId == s_mouseId || !m_pointerIdMapping.contains(mappedId))
         return false;
@@ -285,6 +283,19 @@ bool PointerEventFactory::remove(
     return true;
 }
 
+WillBeHeapVector<int> PointerEventFactory::getPointerIdsOfType(WebPointerProperties::PointerType pointerType)
+{
+    WillBeHeapVector<int> mappedIds;
+
+    for (auto iter = m_pointerIdMapping.begin(); iter != m_pointerIdMapping.end(); ++iter) {
+        int mappedId = iter->key;
+        if (iter->value.incomingId.pointerType() == static_cast<int>(pointerType))
+            mappedIds.append(mappedId);
+    }
+
+    return mappedIds;
+}
+
 bool PointerEventFactory::isPrimary(int mappedId) const
 {
     if (!m_pointerIdMapping.contains(mappedId))