Use 'new' in all the snapshot reallocation functions instead of realloc.

runtime/vm/benchmark_test.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/benchmark_test.h"
 
 #include "bin/builtin.h"
 #include "bin/file.h"
 
 #include "platform/assert.h"
@@ skipping 376 matching lines @@
   EXPECT_VALID(result);
   int64_t elapsed_time = 0;
   result = Dart_IntegerToInt64(result, &elapsed_time);
   EXPECT_VALID(result);
   benchmark->set_score(elapsed_time);
 }
 
 
 static uint8_t* malloc_allocator(
     uint8_t* ptr, intptr_t old_size, intptr_t new_size) {
-  return reinterpret_cast<uint8_t*>(realloc(ptr, new_size));
+  return Utils::Realloc(ptr, old_size, new_size);
 }
 
 
 BENCHMARK(CoreSnapshotSize) {
   const char* kScriptChars =
       "import 'dart:async';\n"
       "import 'dart:core';\n"
       "import 'dart:collection';\n"
       "import 'dart:_collection-dev';\n"
       "import 'dart:math';\n"
@@ skipping 39 matching lines @@
 
   // Write snapshot with object content.
   FullSnapshotWriter writer(&buffer, &malloc_allocator);
   writer.WriteFullSnapshot();
   const Snapshot* snapshot = Snapshot::SetupFromBuffer(buffer);
   ASSERT(snapshot->kind() == Snapshot::kFull);
   benchmark->set_score(snapshot->length());
 }
 
 }  // namespace dart