Added PointerEvent firing on touch events.

Source/core/events/PointerIdManager.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/PointerIdManager.h"
+
+namespace blink {
+
+PointerIdManager::PointerIdManager()
+{
+    clear();
+}
+
+PointerIdManager::~PointerIdManager()
+{
+    clear();
+}
+
+void PointerIdManager::clear()
+{
+    for (int type = 0; type < static_cast<int>(PointerTypeLastEntry); type++) {
+        m_ids[type].clear();
+        m_hasPrimaryId[type] = false;
+    }
+}
+
+void PointerIdManager::add(PointerType type, unsigned id)
+{
+    if (m_ids[type].isEmpty())
+        m_hasPrimaryId[type] = true;
+    m_ids[type].add(id);
+}
+
+void PointerIdManager::remove(PointerType type, unsigned id)
+{
+    if (isPrimary(type, id)) {
+        m_ids[type].removeFirst();
+        m_hasPrimaryId[type] = false;
+    } else {
+        // Note that simply counting the number of ids instead of storing all of them is not enough.
+        // When id is absent, remove() should be a no-op.
+        m_ids[type].remove(id);
+    }
+}
+
+bool PointerIdManager::isPrimary(PointerType type, unsigned id)
+{
+    return m_hasPrimaryId[type] && m_ids[type].first() == id;
+}
+
+} // namespace blink