isolates refactor: this change introduces 'dart:isolate' as a library. This is a

runtime/vm/isolate_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 "platform/assert.h"
 #include "vm/globals.h"
 #include "vm/isolate.h"
 #include "vm/unit_test.h"
 
 namespace dart {
 
 UNIT_TEST_CASE(IsolateCurrent) {
   Isolate* isolate = Isolate::Init(NULL);
   EXPECT_EQ(isolate, Isolate::Current());
   isolate->Shutdown();
   EXPECT_EQ(reinterpret_cast<Isolate*>(NULL), Isolate::Current());
   delete isolate;
 }
 
 
 // Only ia32 and x64 can run dart execution tests.
 #if defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_X64)
 // Unit test case to verify error during isolate spawning (application classes
 // not loaded into the isolate).
 TEST_CASE(IsolateSpawn) {
   const char* kScriptChars =
+      "#import('dart:isolate');\n"
       "class SpawnNewIsolate extends Isolate {\n"
       "  SpawnNewIsolate() : super() { }\n"
       "  void main() {\n"
       "  }\n"
       "  static int testMain() {\n"
       "    try {\n"
       "      new SpawnNewIsolate().spawn().then(function(SendPort port) {\n"
       "      });\n"
       "    } catch (var e) {\n"
       "      throw;\n"
       "    }\n"
       "    return 0;\n"
       "  }\n"
       "}\n";
   Dart_Handle lib = TestCase::LoadTestScript(kScriptChars, NULL);
   Dart_Handle result = Dart_InvokeStatic(lib,
                                          Dart_NewString("SpawnNewIsolate"),
                                          Dart_NewString("testMain"),
                                          0,
                                          NULL);
   EXPECT(Dart_IsError(result));
   EXPECT(Dart_ErrorHasException(result));
   Dart_Handle exception_result = Dart_ErrorGetException(result);
   EXPECT_VALID(exception_result);
 }
 #endif  // defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_X64).
 
 }  // namespace dart