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 40 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 {
-  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() {
-    window.onMessage.listen(_messageHandler);
-    _connected.complete(this);
-  }
-
-  void _messageHandler(msg) {
-    var id = msg.data['id'];
-    var name = msg.data['name'];
-    var data = msg.data['data'];
-    if (name != 'observatoryData') {
-      return;
-    }
-    var completer = _pendingRequests[id];
-    assert(completer != null);
-    _pendingRequests.remove(id);
-    completer.complete(data);
-  }
-
-  Future<String> getString(String path) {
-    var idString = '$_requestSerial';
-    Map message = {};
-    message['id'] = idString;
-    message['method'] = 'observatoryQuery';
-    message['query'] = '$path';
-    _requestSerial++;
-    var completer = new Completer();
-    _pendingRequests[idString] = completer;
-    window.parent.postMessage(JSON.encode(message), '*');
-    return completer.future;
-  }
-}