Don't include LayoutObject.h from FrameView.h

third_party/WebKit/Source/core/layout/DepthOrderedLayoutObjectList.cpp

 // 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.
 
 #include "core/layout/DepthOrderedLayoutObjectList.h"
 
 #include "core/frame/FrameView.h"
 #include "core/layout/LayoutObject.h"
 #include <algorithm>
 
 namespace blink {
 
+struct DepthOrderedLayoutObjectListData {
+    // LayoutObjects sorted by depth (deepest first). This structure is only
+    // populated at the beginning of enumerations. See ordered().
+    Vector<DepthOrderedLayoutObjectList::LayoutObjectWithDepth> m_orderedObjects;
+
+    // Outside of layout, LayoutObjects can be added and removed as needed such
+    // as when style was changed or destroyed. They're kept in this hashset to
+    // keep those operations fast.
+    HashSet<LayoutObject*> m_objects;
+};
+
+DepthOrderedLayoutObjectList::DepthOrderedLayoutObjectList()
+    : m_data(new DepthOrderedLayoutObjectListData)
+{
+}
+
+DepthOrderedLayoutObjectList::~DepthOrderedLayoutObjectList()
+{
+    delete m_data;
+}
+
+int DepthOrderedLayoutObjectList::size() const
+{
+    return m_data->m_objects.size();
+}
+
+bool DepthOrderedLayoutObjectList::isEmpty() const
+{
+    return m_data->m_objects.isEmpty();
+}
+
 void DepthOrderedLayoutObjectList::add(LayoutObject& object)
 {
     ASSERT(!object.frameView()->isInPerformLayout());
-    m_objects.add(&object);
-    m_orderedObjects.clear();
+    m_data->m_objects.add(&object);
+    m_data->m_orderedObjects.clear();
 }
 
 void DepthOrderedLayoutObjectList::remove(LayoutObject& object)
 {
-    auto it = m_objects.find(&object);
-    if (it == m_objects.end())
+    auto it = m_data->m_objects.find(&object);
+    if (it == m_data->m_objects.end())
         return;
     ASSERT(!object.frameView()->isInPerformLayout());
-    m_objects.remove(it);
-    m_orderedObjects.clear();
+    m_data->m_objects.remove(it);
+    m_data->m_orderedObjects.clear();
 }
 
 void DepthOrderedLayoutObjectList::clear()
 {
-    m_objects.clear();
-    m_orderedObjects.clear();
+    m_data->m_objects.clear();
+    m_data->m_orderedObjects.clear();
 }
 
 unsigned DepthOrderedLayoutObjectList::LayoutObjectWithDepth::determineDepth(LayoutObject* object)
 {
     unsigned depth = 1;
     for (LayoutObject* parent = object->parent(); parent; parent = parent->parent())
         ++depth;
     return depth;
 }
 
+const HashSet<LayoutObject*>& DepthOrderedLayoutObjectList::unordered() const
+{
+    return m_data->m_objects;
+}
+
 const Vector<DepthOrderedLayoutObjectList::LayoutObjectWithDepth>& DepthOrderedLayoutObjectList::ordered()
 {
-    if (m_objects.isEmpty() || !m_orderedObjects.isEmpty())
-        return m_orderedObjects;
+    if (m_data->m_objects.isEmpty() || !m_data->m_orderedObjects.isEmpty())
+        return m_data->m_orderedObjects;
 
-    copyToVector(m_objects, m_orderedObjects);
-    std::sort(m_orderedObjects.begin(), m_orderedObjects.end());
-    return m_orderedObjects;
+    copyToVector(m_data->m_objects, m_data->m_orderedObjects);
+    std::sort(m_data->m_orderedObjects.begin(), m_data->m_orderedObjects.end());
+    return m_data->m_orderedObjects;
 }
 
 } // namespace blink