Fix http requests and the crash dump RPC

runtime/vm/service/message.dart

Index: runtime/vm/service/message.dart
diff --git a/runtime/vm/service/message.dart b/runtime/vm/service/message.dart
index d99c4bf8690442cc5687a04bfe20d6a14cf9c2e7..f27a48bf19f65c8e70d5be0958d53e4e89c29932 100644
--- a/runtime/vm/service/message.dart
+++ b/runtime/vm/service/message.dart
@@ -52,12 +52,12 @@ class Message {
   }
 
   Message.fromUri(this.client, Uri uri)
-      : method = _methodNameFromUri(uri) {
+      : serial = '', method = _methodNameFromUri(uri) {
     params.addAll(uri.queryParameters);
   }
 
   Message.forIsolate(this.client, Uri uri, RunningIsolate isolate)
-      : method = _methodNameFromUri(uri) {
+      : serial = '', method = _methodNameFromUri(uri) {
     params.addAll(uri.queryParameters);
     params['isolateId'] = isolate.serviceId;
   }