Rework error handling in the service protocol and in Observatory.

runtime/observatory/tests/service/bad_web_socket_address_test.dart

Index: runtime/observatory/tests/service/bad_web_socket_address_test.dart
diff --git a/runtime/observatory/tests/service/bad_web_socket_address_test.dart b/runtime/observatory/tests/service/bad_web_socket_address_test.dart
index fd259b444911e550b9303485722069db33d9a289..d32831204c4aa5e0f2e37470f7037ff6653d5c4f 100644
--- a/runtime/observatory/tests/service/bad_web_socket_address_test.dart
+++ b/runtime/observatory/tests/service/bad_web_socket_address_test.dart
@@ -3,17 +3,23 @@
 // BSD-style license that can be found in the LICENSE file.
 // VMOptions=--compile-all --error_on_bad_type --error_on_bad_override
 
+import 'package:logging/logging.dart';
 import "package:observatory/service_io.dart";
 import 'package:unittest/unittest.dart';
 
 void testBadWebSocket() {
   var vm = new WebSocketVM(new WebSocketVMTarget('ws://karatekid/ws'));
   vm.load().catchError(expectAsync((error) {
-        expect(error is ServiceException, isTrue);
-      }));
+    expect(error, new isInstanceOf<NetworkRpcException>());
+  }));
 }
 
 main() {
+  Logger.root.level = Level.INFO;
+  Logger.root.onRecord.listen((LogRecord rec) {
+    print('${rec.level.name}: ${rec.time}: ${rec.message}');
+  });
+
   test('bad web socket address', testBadWebSocket);
 }