Make copyToVector() robust against conservative GCs.

third_party/WebKit/Source/wtf/HashCountedSet.h

 /*
  * Copyright (C) 2005, 2006, 2008 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 112 matching lines @@
         return;
 
     m_impl.remove(it);
 }
 
 template <typename T, typename U, typename V, typename W, typename VectorType>
 inline void copyToVector(const HashCountedSet<T, U, V, W>& collection, VectorType& vector)
 {
     typedef typename HashCountedSet<T, U, V, W>::const_iterator iterator;
 
-    vector.resize(collection.size());
+    {
+        // Disallow GC across resize allocation, see crbug.com/568173
+        typename VectorType::GCForbiddenScope scope;
+        vector.resize(collection.size());
+    }
 
     iterator it = collection.begin();
     iterator end = collection.end();
     for (unsigned i = 0; it != end; ++it, ++i)
         vector[i] = *it;
 }
 
 template <typename Value, typename HashFunctions, typename Traits, typename Allocator, size_t inlineCapacity, typename VectorAllocator>
 inline void copyToVector(const HashCountedSet<Value, HashFunctions, Traits, Allocator>& collection, Vector<Value, inlineCapacity, VectorAllocator>& vector)
 {
     typedef typename HashCountedSet<Value, HashFunctions, Traits, Allocator>::const_iterator iterator;
 
-    vector.resize(collection.size());
+    {
+        // Disallow GC across resize allocation, see crbug.com/568173
+        typename Vector<Value, inlineCapacity, VectorAllocator>::GCForbiddenScope scope;
+        vector.resize(collection.size());
+    }
 
     iterator it = collection.begin();
     iterator end = collection.end();
     for (unsigned i = 0; it != end; ++it, ++i)
         vector[i] = (*it).key;
 }
 
 #if !ENABLE(OILPAN)
 template <typename T, typename U, typename V>
 struct NeedsTracing<HashCountedSet<T, U, V>> {
     static const bool value = false;
 };
 #endif
 
 } // namespace WTF
 
 using WTF::HashCountedSet;
 
 #endif // WTF_HashCountedSet_h