Added PointerEvent firing on touch events.

Source/core/events/PointerEventUtils.cpp

+// Copyright 2015 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.
+
+#include "config.h"
+#include "core/events/PointerEventUtils.h"
+
+namespace blink {
+
+PointerIdManager::PointerIdManager()
+{
+    clear();
+}
+
+PointerIdManager::~PointerIdManager()
+{
+    clear();
+}
+
+void PointerIdManager::clear()
+{
+    m_ids.clear();
+    m_hasPrimaryId = false;
+}
+
+void PointerIdManager::add(unsigned id)
+{
+    if (m_ids.isEmpty())
+        m_hasPrimaryId = true;
+    m_ids.add(id);
+}
+
+void PointerIdManager::remove(unsigned id)
+{
+    if (isPrimary(id))
+        m_hasPrimaryId = false;
+    m_ids.remove(id);
+}
+
+bool PointerIdManager::isPrimary(unsigned id)
+{
+    return m_hasPrimaryId && m_ids.first() == id;
+}
+
+} // namespace blink