Begin migrating the vm service from a rest-style interface to a json-rpc style interface.

runtime/observatory/lib/service_html.dart

 // Copyright (c) 2014, 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.
 
 library service_html;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:html';
 import 'dart:typed_data';
@@ skipping 42 matching lines @@
 }
 
 /// The [WebSocketVM] communicates with a Dart VM over WebSocket. The Dart VM
 /// can be embedded in Chromium or standalone. In the case of Chromium, we
 /// make the service requests via the Chrome Remote Debugging Protocol.
 class WebSocketVM extends CommonWebSocketVM {
   WebSocketVM(WebSocketVMTarget target) : super(target, new _HtmlWebSocket());
 }
 
 // A VM that communicates with the service via posting messages from DevTools.
 class PostMessageVM extends VM {

[Cutch, 2015/02/02 22:20:04]

This whole class should die now.

[turnidge, 2015/02/02 22:44:05]

Done.

   final Completer _connected = new Completer();
   final Completer _disconnected = new Completer();
   void disconnect() { /* nope */ }
   Future get onConnect => _connected.future;
   Future get onDisconnect => _disconnected.future;
   final Map<String, Completer> _pendingRequests =
       new Map<String, Completer>();
   int _requestSerial = 0;
 
   PostMessageVM() : super() {
@@ skipping 19 matching lines @@
     Map message = {};
     message['id'] = idString;
     message['method'] = 'observatoryQuery';
     message['query'] = '$path';
     _requestSerial++;
     var completer = new Completer();
     _pendingRequests[idString] = completer;
     window.parent.postMessage(JSON.encode(message), '*');
     return completer.future;
   }
+
+  Future<String> invokeRpcRaw(String method, Map params) {
+    throw 'not-implemented';
+  }
 }