Rename and improve "traceable" templates.

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 1001 matching lines @@
 {
     size_t allocSize = size * sizeof(ValueType);
     ValueType* result;
     // Assert that we will not use memset on things with a vtable entry.  The
     // compiler will also check this on some platforms. We would like to check
     // this on the whole value (key-value pair), but std::is_polymorphic will return
     // false for a pair of two types, even if one of the components is
     // polymorphic.
     static_assert(!Traits::emptyValueIsZero || !std::is_polymorphic<KeyType>::value, "empty value cannot be zero for things with a vtable");
     static_assert(Allocator::isGarbageCollected
-        || ((!AllowsOnlyPlacementNew<KeyType>::value || !NeedsTracing<KeyType>::value)
-        && (!AllowsOnlyPlacementNew<ValueType>::value || !NeedsTracing<ValueType>::value))
+        || ((!AllowsOnlyPlacementNew<KeyType>::value || !IsTraceable<KeyType>::value)
+        && (!AllowsOnlyPlacementNew<ValueType>::value || !IsTraceable<ValueType>::value))
         , "Cannot put DISALLOW_NEW_EXCEPT_PLACEMENT_NEW objects that have trace methods into an off-heap HashTable");
 
     if (Traits::emptyValueIsZero) {
         result = Allocator::template allocateZeroedHashTableBacking<ValueType, HashTable>(allocSize);
     } else {
         result = Allocator::template allocateHashTableBacking<ValueType, HashTable>(allocSize);
         for (unsigned i = 0; i < size; i++)
             initializeBucket(result[i]);
     }
     return result;
@@ skipping 365 matching lines @@
     // needed.
     if (Traits::weakHandlingFlag == NoWeakHandlingInCollections) {
         Allocator::markNoTracing(visitor, m_table);
     } else {
         Allocator::registerDelayedMarkNoTracing(visitor, m_table);
         // Since we're delaying marking this HashTable, it is possible that the
         // registerWeakMembers is called multiple times (in rare
         // cases). However, it shouldn't cause any issue.
         Allocator::registerWeakMembers(visitor, this, m_table, WeakProcessingHashTableHelper<Traits::weakHandlingFlag, Key, Value, Extractor, HashFunctions, Traits, KeyTraits, Allocator>::process);
     }
-    if (!NeedsTracingTrait<Traits>::value)
+    if (!IsTraceableInCollectionTrait<Traits>::value)
         return;
     if (Traits::weakHandlingFlag == WeakHandlingInCollections) {
         // If we have both strong and weak pointers in the collection then
         // we queue up the collection for fixed point iteration a la
         // Ephemerons:
         // http://dl.acm.org/citation.cfm?doid=263698.263733 - see also
         // http://www.jucs.org/jucs_14_21/eliminating_cycles_in_weak
         ASSERT(!enqueued() || Allocator::weakTableRegistered(visitor, this));
         if (!enqueued()) {
             Allocator::registerWeakTable(visitor, this,
@@ skipping 115 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