Replace RenderArena with PartitionAlloc.

Source/wtf/PartitionAlloc.cpp

 /*
  * 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 299 matching lines @@
     } else {
         // Fully used page became partially used. It must be put back on the
         // non-full page list.
         partitionLinkPage(page, bucket->currPage);
         page->numAllocatedSlots = -page->numAllocatedSlots - 2;
         ASSERT(page->numAllocatedSlots == partitionBucketSlots(bucket) - 1);
         --bucket->numFullPages;
     }
 }
 
+size_t partitionAllocGetUsedPagesSize(const PartitionRoot& root)
+{
+    size_t total = 0;
+    size_t i;
+    for (i = 0; i < kNumBuckets; ++i) {
+        const PartitionBucket& bucket = root.buckets[i];
+        total += bucket.numFullPages * kPartitionPageSize;
+        const PartitionPageHeader* page = bucket.currPage;
+        do {
+            if (page != &bucket.root->seedPage)
+                total += kPartitionPageSize;
+            page = page->next;
+        } while (page != bucket.currPage);
+    }
+    return total;
+}
+
 #ifndef NDEBUG
 
 void partitionDumpStats(const PartitionRoot& root)
 {
     size_t i;
     for (i = 0; i < kNumBuckets; ++i) {
         const PartitionBucket& bucket = root.buckets[i];
         if (bucket.currPage == &bucket.root->seedPage && !bucket.freePages) {
             // Empty bucket with no freelist pages. Skip reporting it.
             continue;
@@ skipping 16 matching lines @@
             }
             page = page->next;
         } while (page != bucket.currPage);
         printf("bucket size %ld: %ld/%ld bytes, %ld free pages\n", bucketSlotSize, numActiveBytes, numActivePages * kPartitionPageSize, numFreePages);
     }
 }
 #endif // !NDEBUG
 
 } // namespace WTF