V8ScriptValueSerializer: Use PartitionAlloc for the buffer, and avoid copying it into a String.

third_party/WebKit/Source/wtf/allocator/Partitions.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 72 matching lines @@
 
   static void decommitFreeableMemory();
 
   static void reportMemoryUsageHistogram();
 
   static void dumpMemoryStats(bool isLightDump, PartitionStatsDumper*);
 
   ALWAYS_INLINE static void* bufferMalloc(size_t n, const char* typeName) {
     return partitionAllocGeneric(bufferPartition(), n, typeName);
   }
+  ALWAYS_INLINE static void* bufferRealloc(void* p,
+                                           size_t n,
+                                           const char* typeName) {
+    return partitionReallocGeneric(bufferPartition(), p, n, typeName);

[haraken, 2016/11/11 03:50:01]

Can we add a unit test to PartitionAllocTest?

[jbroman, 2016/11/11 16:14:58]

What kind of test would you want? We don't currently have unit tests for the
other shorthands (bufferMalloc, bufferFree, etc., which fill in one parameter of
the generic functions), and partitionReallocGeneric is covered by
PartitionAllocTest.GenericAlloc and PartitionAllocTest.Realloc.

+  }
   ALWAYS_INLINE static void bufferFree(void* p) {
     partitionFreeGeneric(bufferPartition(), p);
   }
   ALWAYS_INLINE static size_t bufferActualSize(size_t n) {
     return partitionAllocActualSize(bufferPartition(), n);
   }
   static void* fastMalloc(size_t n, const char* typeName) {
     return partitionAllocGeneric(Partitions::fastMallocPartition(), n,
                                  typeName);
   }
@@ skipping 30 matching lines @@
   //   - Fast malloc partition: A partition to allocate all other objects.
   static PartitionAllocatorGeneric m_fastMallocAllocator;
   static PartitionAllocatorGeneric m_bufferAllocator;
   static SizeSpecificPartitionAllocator<1024> m_layoutAllocator;
   static ReportPartitionAllocSizeFunction m_reportSizeFunction;
 };
 
 }  // namespace WTF
 
 #endif  // Partitions_h