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

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef PointerEventFactory_h
 #define PointerEventFactory_h
 
 #include "core/CoreExport.h"
 #include "core/events/PointerEvent.h"
 #include "public/platform/WebPointerProperties.h"
@@ skipping 22 matching lines @@
         const AtomicString& mouseEventName, const PlatformMouseEvent&,
         PassRefPtrWillBeRawPtr<EventTarget> relatedTarget,
         PassRefPtrWillBeRawPtr<AbstractView>);
 
     PassRefPtrWillBeRawPtr<PointerEvent> create(const AtomicString& type,
         const PlatformTouchPoint&, PlatformEvent::Modifiers,
         const double width, const double height,
         const double clientX, const double clientY);
 
     PassRefPtrWillBeRawPtr<PointerEvent> createPointerCancel(
-        const PlatformTouchPoint&);
+        const int pointerId, const WebPointerProperties::PointerType);
 
     PassRefPtrWillBeRawPtr<PointerEvent> create(
         PassRefPtrWillBeRawPtr<PointerEvent>,
         const AtomicString& type,
         PassRefPtrWillBeRawPtr<EventTarget>);
 
     // Clear all the existing ids.
     void clear();
 
-    // Returns true if pointerEvent is removed. When a pointerEvent with a
-    // particular id is removed that id is considered free even though there
-    // might have been other PointerEvents that were generated with the same id
-    // before.
-    bool remove(const PassRefPtrWillBeRawPtr<PointerEvent>);
+    // When a particular pointerId is removed that id is considered free even
+    // though there might have been other PointerEvents that were generated with
+    // the same id before.
+    bool remove(const int);
+
+    // Returns all ids of the given pointerType.
+    WillBeHeapVector<int> getPointerIdsOfType(WebPointerProperties::PointerType);
 
     // Returns whether a pointer id exists and active
     bool isActive(const int);
 
     // Returns whether a pointer id exists and has at least one pressed button
     bool isActiveButtonsState(const int);
 
 private:
     typedef WTF::UnsignedWithZeroKeyHashTraits<int> UnsignedHash;
     typedef struct IncomingId : public std::pair<int, int> {
@@ skipping 24 matching lines @@
     int m_currentId;
     HashMap<IncomingId, int, WTF::PairHash<int, int>, WTF::PairHashTraits<UnsignedHash, UnsignedHash>> m_pointerIncomingIdMapping;
     HashMap<int, PointerAttributes, WTF::IntHash<int>, UnsignedHash> m_pointerIdMapping;
     int m_primaryId[static_cast<int>(WebPointerProperties::PointerType::LastEntry) + 1];
     int m_idCount[static_cast<int>(WebPointerProperties::PointerType::LastEntry) + 1];
 };
 
 } // namespace blink
 
 #endif // PointerEventFactory_h