Revert "Hide Isolate pointer from embedder"

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"
-#include "vm/dart_api_impl.h"
 #include "vm/globals.h"
 #include "vm/heap.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
 #include "vm/zone.h"
 
 namespace dart {
 
 DECLARE_FLAG(int, code_heap_size);
 DECLARE_FLAG(int, old_gen_growth_space_ratio);
@@ skipping 49 matching lines @@
       tail_->next_ = this;
     }
     tail_ = this;
   }
 
   // Accessors.
   const char* name() const { return name_; }
   const char* score_kind() const { return score_kind_; }
   void set_score(int64_t value) { score_ = value; }
   int64_t score() const { return score_; }
-  Isolate* isolate() const { return Api::CastIsolate(isolate_); }
+  Isolate* isolate() const { return reinterpret_cast<Isolate*>(isolate_); }
 
   Dart_Isolate CreateIsolate(const uint8_t* buffer) {
     char* err = NULL;
     isolate_ = Dart_CreateIsolate(NULL, NULL, buffer, NULL, &err);
-    EXPECT(isolate_ != DART_ILLEGAL_ISOLATE);
+    EXPECT(isolate_ != NULL);
     free(err);
     return isolate_;
   }
 
   void Run() { (*run_)(this); }
   void RunBenchmark();
 
   static void RunAll(const char* executable);
   static void SetExecutable(const char* arg) { executable_ = arg; }
   static const char* Executable() { return executable_; }
@@ skipping 30 matching lines @@
 
  private:
   Benchmark* benchmark_;
 
   DISALLOW_COPY_AND_ASSIGN(BenchmarkIsolateScope);
 };
 
 }  // namespace dart
 
 #endif  // VM_BENCHMARK_TEST_H_