Support for synchronizing assets onto a DevFS
diff --git a/packages/flutter_tools/test/src/mocks.dart b/packages/flutter_tools/test/src/mocks.dart
index 49706e7..a384ea1 100644
--- a/packages/flutter_tools/test/src/mocks.dart
+++ b/packages/flutter_tools/test/src/mocks.dart
@@ -75,6 +75,8 @@
   final List<String> messages = new List<String>();
 
   bool contains(String match) {
+    print('Checking for `$match` in:');
+    print(messages);
     bool result = messages.contains(match);
     messages.clear();
     return result;
@@ -97,6 +99,11 @@
   }
 
   @override
+  Future<dynamic> deleteFile(String fsName, DevFSEntry entry) async {
+    messages.add('deleteFile $fsName ${entry.devicePath}');
+  }
+
+  @override
   Future<dynamic> writeSource(String fsName,
                               String devicePath,
                               String contents) async {