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

runtime/observatory/lib/service_common.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_common;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:typed_data';
 
@@ skipping 36 matching lines @@
     return {
       'lastConnectionTime': lastConnectionTime,
       'chrome': chrome,
       'name': name,
       'networkAddress': networkAddress,
     };
   }
 }
 
 class _WebSocketRequest {
-  final String id;
+  final String method;
+  final Map params;
   final Completer<String> completer;
-  _WebSocketRequest(this.id)
+
+   _WebSocketRequest.old(this.method)
+      : params = null, completer = new Completer<String>();
+
+   _WebSocketRequest.rpc(this.method, this.params)
       : completer = new Completer<String>();
 }
 
 /// Minimal common interface for 'WebSocket' in [dart:io] and [dart:html].
 abstract class CommonWebSocket {
   void connect(String address,
                void onOpen(),
                void onMessage(dynamic data),
                void onError(),
                void onClose());
@@ skipping 60 matching lines @@
           target.networkAddress, _onOpen, _onMessage, _onError, _onClose);
     }
     return _makeRequest(id);
   }
 
   /// Add a request for [id] to pending requests.
   Future<String> _makeRequest(String id) {
     assert(_hasInitiatedConnect);
     // Create request.
     String serial = (_requestSerial++).toString();
-    var request = new _WebSocketRequest(id);
+    var request = new _WebSocketRequest.old(id);
     if (_webSocket.isOpen) {
       // Already connected, send request immediately.
       _sendRequest(serial, request);
+    } else {
+      // Not connected yet, add to delayed requests.
+      _delayedRequests[serial] = request;
+    }
+    return request.completer.future;
+  }
+
+  Future<String> invokeRpcRaw(String method, Map params) {
+    if (!_hasInitiatedConnect) {
+      _hasInitiatedConnect = true;
+      _webSocket.connect(
+          target.networkAddress, _onOpen, _onMessage, _onError, _onClose);
+    }
+    String serial = (_requestSerial++).toString();
+    var request = new _WebSocketRequest.rpc(method, params);
+    if (_webSocket.isOpen) {
+      // Already connected, send request immediately.
+      _sendRequest(serial, request);
     } else {
       // Not connected yet, add to delayed requests.
       _delayedRequests[serial] = request;
     }
     return request.completer.future;
   }
 
   void _onClose() {
     _cancelAllRequests();
     _notifyDisconnect();
@@ skipping 42 matching lines @@
     var serial;
     var response;
     if (target.chrome) {
       if (map['method'] != 'Dart.observatoryData') {
         // ignore devtools protocol spam.
         return;
       }
       serial = map['params']['id'].toString();
       response = map['params']['data'];
     } else {
-      serial = map['seq'];
+      serial = map['id'];
       response = map['response'];
     }
     if (serial == null) {
       // Messages without sequence numbers are asynchronous events
       // from the vm.
       postEventMessage(response);
       return;
     }
     // Complete request.
     var request = _pendingRequests.remove(serial);
@@ skipping 42 matching lines @@
     Logger.root.info('Sending all delayed requests.');
     // Send all delayed requests.
     _delayedRequests.forEach(_sendRequest);
     // Clear all delayed requests.
     _delayedRequests.clear();
   }
 
   /// Send the request over WebSocket.
   void _sendRequest(String serial, _WebSocketRequest request) {
     assert (_webSocket.isOpen);
-    if (!request.id.endsWith('/profile/tag')) {
-      Logger.root.info('GET ${request.id} from ${target.networkAddress}');
+    if (request.method != 'getTagProfile') {
+      Logger.root.info('GET ${request.method} from ${target.networkAddress}');
     }
     // Mark request as pending.
     assert(_pendingRequests.containsKey(serial) == false);
     _pendingRequests[serial] = request;
     var message;
     // Encode message.
     if (target.chrome) {
       message = JSON.encode({
         'id': int.parse(serial),
         'method': 'Dart.observatoryQuery',
         'params': {
           'id': serial,
-          'query': request.id
+          'query': request.method
         }
       });
     } else {
-      message = JSON.encode({'seq': serial, 'request': request.id});
+      message = JSON.encode({'id': serial,
+                             'method': request.method,
+                             'params': request.params});
     }
     // Send message.
     _webSocket.send(message);
   }
 }