Implement automatic loading of dart:core_native_fields library

vm/unit_test.cc

 // Copyright (c) 2011, 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 <stdio.h>
 
 #include "vm/unit_test.h"
 
 #include "vm/assembler.h"
 #include "vm/ast_printer.h"
@@ skipping 30 matching lines @@
 
 void TestCaseBase::RunAll() {
   TestCaseBase* test = first_;
   while (test != NULL) {
     test->RunTest();
     test = test->next_;
   }
 }
 
 
+static Dart_Handle LibraryTagHandler(Dart_LibraryTag tag,
+                                     Dart_Handle library,
+                                     Dart_Handle url) {
+  if (tag == kCanonicalizeUrl) {
+    return url;
+  }
+  return Dart_LookupLibrary(url);
+}
+
+
 Dart_Handle TestCase::LoadTestScript(const char* script,
                                      Dart_NativeEntryResolver resolver) {
   Dart_Handle url = Dart_NewString(TestCase::url());
   Dart_Handle source = Dart_NewString(script);
-  Dart_Handle lib = Dart_LoadScript(url, source, NULL);
+  Dart_Handle lib = Dart_LoadScript(url, source, LibraryTagHandler);
   ASSERT(Dart_IsValid(lib));
   Dart_Handle result = Dart_SetNativeResolver(lib, resolver);
   ASSERT(Dart_IsValid(result));
   return lib;
 }
 
 
 Dart_Handle TestCase::lib() {
   Dart_Handle url = Dart_NewString(TestCase::url());
   Dart_Handle lib = Dart_LookupLibrary(url);
@@ skipping 109 matching lines @@
     Compiler::CompileFunction(function);
     retval = true;
   } else {
     retval = false;
   }
   isolate->set_long_jump_base(base);
   return retval;
 }
 
 }  // namespace dart