Disallow off-heap containers containing raw on-heap pointers.

third_party/WebKit/Source/wtf/HashMap.h

 /*
  * Copyright (C) 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 60 matching lines @@
                     HashFunctions,
                     ValueTraits,
                     KeyTraits,
                     Allocator>
       HashTableType;
 
   class HashMapKeysProxy;
   class HashMapValuesProxy;
 
  public:
+  HashMap() {
+    static_assert(Allocator::isGarbageCollected ||
+                      !IsPointerToGarbageCollectedType<KeyArg>::value,
+                  "Cannot put raw pointers to garbage-collected classes into "
+                  "an off-heap HashMap.  Use HeapHashMap<> instead.");
+    static_assert(Allocator::isGarbageCollected ||
+                      !IsPointerToGarbageCollectedType<MappedArg>::value,
+                  "Cannot put raw pointers to garbage-collected classes into "
+                  "an off-heap HashMap.  Use HeapHashMap<> instead.");
+  }
+
   typedef HashTableIteratorAdapter<HashTableType, ValueType> iterator;
   typedef HashTableConstIteratorAdapter<HashTableType, ValueType>
       const_iterator;
   typedef typename HashTableType::AddResult AddResult;
 
- public:
   void swap(HashMap& ref) { m_impl.swap(ref.m_impl); }
 
   unsigned size() const;
   unsigned capacity() const;
   void reserveCapacityForSize(unsigned size) {
     m_impl.reserveCapacityForSize(size);
   }
 
   bool isEmpty() const;
 
@@ skipping 593 matching lines @@
   iterator end = collection.end().values();
   for (unsigned i = 0; it != end; ++it, ++i)
     vector[i] = *it;
 }
 
 }  // namespace WTF
 
 using WTF::HashMap;
 
 #endif  // WTF_HashMap_h