Retire GC lockout on initializing hash buckets.

third_party/WebKit/Source/wtf/HashTable.h

 /*
  * Copyright (C) 2005, 2006, 2007, 2008, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008 David Levin <levin@chromium.org>
  *
  * 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,
@@ skipping 773 matching lines @@
         // makes it possible to use this with types that don't support copying.
         // The memset to 0 looks like a slow operation but is optimized by the
         // compilers.
         memset(&bucket, 0, sizeof(bucket));
     }
 };
 
 template <typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits, typename Allocator>
 inline void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits, Allocator>::initializeBucket(ValueType& bucket)
 {
-    // The key and value cannot be initialied atomically, and it would be wrong
-    // to have a GC when only one was initialized and the other still contained
-    // garbage (eg. from a previous use of the same slot).  Therefore we forbid
-    // a GC while both the key and the value are initialized.
-    Allocator::enterGCForbiddenScope();
     HashTableBucketInitializer<Traits::emptyValueIsZero>::template initialize<Traits>(bucket);
-    Allocator::leaveGCForbiddenScope();
 }
 
 template <typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits, typename Allocator>
 template <typename HashTranslator, typename T, typename Extra>
 typename HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits, Allocator>::AddResult HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits, Allocator>::add(const T& key, const Extra& extra)
 {
     ASSERT(Allocator::isAllocationAllowed());
     if (!m_table)
         expand();
 
@@ skipping 652 matching lines @@
     CollectionIterator end(toBeRemoved.end());
     for (CollectionIterator it(toBeRemoved.begin()); it != end; ++it)
         collection.remove(*it);
 }
 
 } // namespace WTF
 
 #include "wtf/HashIterators.h"
 
 #endif // WTF_HashTable_h