Implement recursive directory deletion.

runtime/bin/directory.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/directory.h"
 
 #include "bin/dartutils.h"
 #include "include/dart_api.h"
 #include "platform/assert.h"
 
@@ skipping 103 matching lines @@
     }
     Dart_SetReturnValue(args, Dart_Null());
   }
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(Directory_Delete)(Dart_NativeArguments args) {
   Dart_EnterScope();
   Dart_Handle path = Dart_GetNativeArgument(args, 0);
-  if (Dart_IsString(path)) {
-    bool deleted = Directory::Delete(DartUtils::GetStringValue(path));
+  Dart_Handle recursive = Dart_GetNativeArgument(args, 1);
+  if (Dart_IsString(path) && Dart_IsBoolean(recursive)) {
+    bool deleted = Directory::Delete(DartUtils::GetStringValue(path),
+                                     DartUtils::GetBooleanValue(recursive));
     Dart_SetReturnValue(args, Dart_NewBoolean(deleted));
   } else {
     Dart_SetReturnValue(args, Dart_NewBoolean(false));
   }
   Dart_ExitScope();
 }