Dart: Reorganize files

mojo/dart/test/exception_test.dart

Index: mojo/dart/test/exception_test.dart
diff --git a/mojo/dart/test/exception_test.dart b/mojo/dart/test/exception_test.dart
deleted file mode 100644
index f62540e0535abdcd838721d724ba8c93ab1c96c8..0000000000000000000000000000000000000000
--- a/mojo/dart/test/exception_test.dart
+++ /dev/null
@@ -1,14 +0,0 @@
-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-import 'package:mojo/core.dart';
-
-main() {
-  try {
-    throw 'exception';
-  } catch (exception, stackTrace) {
-    assert(exception == 'exception');
-    assert(stackTrace != null);
-  }
-}