Add Dart_GetStickyError

runtime/vm/dart_api_impl_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 "bin/builtin.h"
 #include "vm/compiler.h"
 #include "include/dart_api.h"
 #include "include/dart_mirrors_api.h"
 #include "include/dart_native_api.h"
 #include "include/dart_tools_api.h"
@@ skipping 3619 matching lines @@
 
 
 TEST_CASE(SetStickyError) {
     const char* kScriptChars =
       "main() => throw 'HI';";
   Dart_Handle lib = TestCase::LoadTestScript(kScriptChars, NULL);
   Dart_Handle retobj = Dart_Invoke(lib, NewString("main"), 0, NULL);
   EXPECT(Dart_IsError(retobj));
   EXPECT(Dart_IsUnhandledExceptionError(retobj));
   EXPECT(!Dart_HasStickyError());
+  EXPECT(Dart_GetStickyError() == Dart_Null());
   Dart_SetStickyError(retobj);
   EXPECT(Dart_HasStickyError());
+  EXPECT(Dart_GetStickyError() != Dart_Null());
+  Dart_SetStickyError(Dart_Null());
+  EXPECT(!Dart_HasStickyError());
+  EXPECT(Dart_GetStickyError() == Dart_Null());
 }
 
 
 TEST_CASE(TypeGetNonParamtericTypes) {
   const char* kScriptChars =
       "class MyClass0 {\n"
       "}\n"
       "\n"
       "class MyClass1 implements MyInterface1 {\n"
       "}\n"
@@ skipping 6559 matching lines @@
   result = Dart_Invoke(lib,
                        NewString("foozoo"),
                        0,
                        NULL);
   EXPECT(Dart_IsError(result));
 }
 
 #endif  // !PRODUCT
 
 }  // namespace dart