Remove vmservice_patch.dart.

sdk/lib/vmservice/message.dart

Index: sdk/lib/vmservice/message.dart
diff --git a/sdk/lib/vmservice/message.dart b/sdk/lib/vmservice/message.dart
index 3b31682c4a06890e8cc5f8e74ef3615f00b35771..a86dc388aeacd29cfaf585e18d429bc1c1bcc7a2 100644
--- a/sdk/lib/vmservice/message.dart
+++ b/sdk/lib/vmservice/message.dart
@@ -188,6 +188,10 @@ class Message {
   }
 }
 
-external bool sendIsolateServiceMessage(SendPort sp, List m);
-external void sendRootServiceMessage(List m);
-external void sendObjectRootServiceMessage(List m);
+bool sendIsolateServiceMessage(SendPort sp, List m)
+    native "VMService_SendIsolateServiceMessage";
+
+void sendRootServiceMessage(List m) native "VMService_SendRootServiceMessage";
+
+void sendObjectRootServiceMessage(List m)
+    native "VMService_SendObjectRootServiceMessage";