Migrate most uses of StackZone(Isolate*) to Thread*.

runtime/vm/benchmark_test.h

 // 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.
 
 #ifndef VM_BENCHMARK_TEST_H_
 #define VM_BENCHMARK_TEST_H_
 
 #include "include/dart_api.h"
 
 #include "vm/dart.h"
@@ skipping 20 matching lines @@
 
 // The BENCHMARK macros are used for benchmarking a specific functionality
 // of the VM.
 #define BENCHMARK_HELPER(name, kind)                                           \
   void Dart_Benchmark##name(Benchmark* benchmark);                             \
   static Benchmark kRegister##name(Dart_Benchmark##name, #name, kind);         \
   static void Dart_BenchmarkHelper##name(Benchmark* benchmark);                \
   void Dart_Benchmark##name(Benchmark* benchmark) {                            \
     FLAG_old_gen_growth_space_ratio = 100;                                     \
     BenchmarkIsolateScope __isolate__(benchmark);                              \
-    StackZone __zone__(benchmark->isolate());                                  \
-    HandleScope __hs__(benchmark->isolate());                                  \
+    Thread* __thread__ = Thread::Current();                                    \
+    ASSERT(__thread__->isolate() == benchmark->isolate());                     \
+    StackZone __zone__(__thread__);                                            \
+    HandleScope __hs__(__thread__);                                            \
     Dart_BenchmarkHelper##name(benchmark);                                     \
   }                                                                            \
   static void Dart_BenchmarkHelper##name(Benchmark* benchmark)
 
 #define BENCHMARK(name) BENCHMARK_HELPER(name, "RunTime")
 #define BENCHMARK_SIZE(name) BENCHMARK_HELPER(name, "CodeSize")
 
 
 inline Dart_Handle NewString(const char* str) {
   return Dart_NewStringFromCString(str);
@@ skipping 73 matching lines @@
 
  private:
   Benchmark* benchmark_;
 
   DISALLOW_COPY_AND_ASSIGN(BenchmarkIsolateScope);
 };
 
 }  // namespace dart
 
 #endif  // VM_BENCHMARK_TEST_H_