Replace RenderArena with PartitionAlloc.

Source/wtf/PartitionAlloc.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 119 matching lines @@
     PartitionBucket seedBucket;
     PartitionBucket buckets[kNumBuckets];
     char* nextSuperPage;
     char* nextPartitionPage;
     char* nextPartitionPageEnd;
     bool initialized;
 };
 
 WTF_EXPORT void partitionAllocInit(PartitionRoot*);
 WTF_EXPORT void partitionAllocShutdown(PartitionRoot*);
+WTF_EXPORT size_t partitionAllocGetUsedPagesSize(const PartitionRoot&);
 
 WTF_EXPORT NEVER_INLINE void* partitionAllocSlowPath(PartitionBucket*);
 WTF_EXPORT NEVER_INLINE void partitionFreeSlowPath(PartitionPageHeader*);
 
 ALWAYS_INLINE PartitionFreelistEntry* partitionFreelistMask(PartitionFreelistEntry* ptr)
 {
     // For now, use a simple / fast mask that guarantees an invalid pointer in
     // case it gets used as a vtable pointer.
     // The one attack we're fully mitigating is where an object is freed and its
     // vtable used where the attacker doesn't get the chance to run allocations
@@ skipping 66 matching lines @@
 
 } // namespace WTF
 
 using WTF::PartitionRoot;
 using WTF::partitionAllocInit;
 using WTF::partitionAllocShutdown;
 using WTF::partitionAlloc;
 using WTF::partitionFree;
 
 #endif // WTF_PartitionAlloc_h