Refactor the dart api a bit:

runtime/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 34 matching lines @@
     test->RunTest();
     test = test->next_;
   }
 }
 
 
 Dart_Handle TestCase::LoadTestScript(const char* script,
                                      Dart_NativeEntryResolver resolver) {
   Dart_Handle url = Dart_NewString(TestCase::url());
   Dart_Handle source = Dart_NewString(script);
-  Dart_Result result = Dart_LoadScript(url, source, NULL);
-  assert(Dart_IsValidResult(result));
-  Dart_Handle lib = Dart_GetResult(result);
-  result = Dart_SetNativeResolver(lib, resolver);
-  assert(Dart_IsValidResult(result));
+  Dart_Handle lib = Dart_LoadScript(url, source, NULL);
+  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_Result result = Dart_LookupLibrary(url);
-  assert(Dart_IsValidResult(result));
-  Dart_Handle lib = Dart_GetResult(result);
-  assert(Dart_IsLibrary(lib));
+  Dart_Handle lib = Dart_LookupLibrary(url);
+  ASSERT(Dart_IsValid(lib));
+  ASSERT(Dart_IsLibrary(lib));
   return lib;
 }
 
 
 uword AssemblerTest::Assemble() {
   const Code& code = Code::Handle(Code::FinalizeCode(name_, assembler_));
   if (FLAG_disassemble) {
     OS::Print("Code for test '%s' {\n", name_);
     const Instructions& instructions =
         Instructions::Handle(code.instructions());
@@ skipping 97 matching lines @@
     Compiler::CompileFunction(function);
     retval = true;
   } else {
     retval = false;
   }
   isolate->set_long_jump_base(base);
   return retval;
 }
 
 }  // namespace dart