Use C++11 features in core/html

Source/core/html/canvas/HitRegion.cpp

 // Copyright 2014 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/html/canvas/HitRegion.h"
 
 #include "core/accessibility/AXObjectCache.h"
 #include "core/rendering/RenderBoxModelObject.h"
 
@@ skipping 116 matching lines @@
 HitRegion* HitRegionManager::getHitRegionById(const String& id) const
 {
     return m_hitRegionIdMap.get(id);
 }
 
 HitRegion* HitRegionManager::getHitRegionByControl(Element* control) const
 {
     if (control)
         return m_hitRegionControlMap.get(control);
 
-    return 0;
+    return nullptr;
 }
 
 HitRegion* HitRegionManager::getHitRegionAtPoint(const LayoutPoint& point) const
 {
     HitRegionIterator itEnd = m_hitRegionList.rend();
 
     for (HitRegionIterator it = m_hitRegionList.rbegin(); it != itEnd; ++it) {
         RefPtrWillBeRawPtr<HitRegion> hitRegion = *it;
         if (hitRegion->contains(point))
             return hitRegion.get();
     }
 
-    return 0;
+    return nullptr;
 }
 
 unsigned HitRegionManager::getHitRegionsCount() const
 {
     return m_hitRegionList.size();
 }
 
 void HitRegionManager::trace(Visitor* visitor)
 {
 #if ENABLE(OILPAN)
     visitor->trace(m_hitRegionList);
     visitor->trace(m_hitRegionIdMap);
     visitor->trace(m_hitRegionControlMap);
 #endif
 }
 
 DEFINE_EMPTY_DESTRUCTOR_WILL_BE_REMOVED(HitRegionManager)
 
 } // namespace blink