Fix strong mode error in test.

Closes https://github.com/dart-lang/source_maps/issues/21

BUG=
R=sigmund@google.com

Review URL: https://codereview.chromium.org//2565053002 .

pkgs/source_maps/CHANGELOG.md

diff --git a/pkgs/source_maps/CHANGELOG.md b/pkgs/source_maps/CHANGELOG.md
index e5f3ae2..425e7ae 100644
--- a/pkgs/source_maps/CHANGELOG.md
+++ b/pkgs/source_maps/CHANGELOG.md
@@ -1,3 +1,6 @@
+## 0.10.1+5
+ * Fix strong mode warning in test.
+
 ## 0.10.1+4
 
 * Extend `MappingBundle.spanFor` to accept requests for output files that

pkgs/source_maps/pubspec.yaml

diff --git a/pkgs/source_maps/pubspec.yaml b/pkgs/source_maps/pubspec.yaml
index d0d455f..3beb3ea 100644
--- a/pkgs/source_maps/pubspec.yaml
+++ b/pkgs/source_maps/pubspec.yaml
@@ -1,5 +1,5 @@
 name: source_maps
-version: 0.10.1+4
+version: 0.10.1+5
 author: Dart Team <misc@dartlang.org>
 description: Library to programmatically manipulate source map files.
 homepage: http://github.com/dart-lang/source_maps

pkgs/source_maps/test/parser_test.dart

diff --git a/pkgs/source_maps/test/parser_test.dart b/pkgs/source_maps/test/parser_test.dart
index a317f7e..4b2d947 100644
--- a/pkgs/source_maps/test/parser_test.dart
+++ b/pkgs/source_maps/test/parser_test.dart
@@ -250,7 +250,7 @@
       expect(mapping.toJson(), equals(expected));
     }
     // Invalid for this case
-    expect(() => parseJson(SOURCE_MAP_BUNDLE), throws);
+    expect(() => parseJson(SOURCE_MAP_BUNDLE as dynamic), throws);
 
     var mapping = parseJsonExtended(SOURCE_MAP_BUNDLE);
     expect(mapping.toJson(), equals(SOURCE_MAP_BUNDLE));