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

runtime/vm/service/running_isolates.dart

 // Copyright (c) 2013, 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.
 
 part of vmservice;
 
 class RunningIsolates implements MessageRouter {
   final Map<int, RunningIsolate> isolates = new Map<int, RunningIsolate>();
   int _rootPortId;
 
   RunningIsolates();
 
   void isolateStartup(int portId, SendPort sp, String name) {
     if (_rootPortId == null) {
       _rootPortId = portId;
     }
     var ri = new RunningIsolate(portId, sp, name);
     isolates[portId] = ri;
   }
 
   void isolateShutdown(int portId, SendPort sp) {
     if (_rootPortId == portId) {
       _rootPortId = null;
     }
     isolates.remove(portId);
   }
 
   Future<String> route(Message message) {
+    if (message.isOld) {
+      return routeOld(message);
+    }
+
+    String isolateParam = message.params['isolate'];
+    int isolateId;
+    if (!isolateParam.startsWith('isolates/')) {
+      message.setErrorResponse('Malformed isolate id $isolateParam');
+      return message.response;
+    }
+    isolateParam = isolateParam.substring('isolates/'.length);
+    if (isolateParam == 'isolates/root') {
+      isolateId = _rootPortId;
+    } else {
+      try {
+        isolateId = int.parse(isolateParam);
+      } catch (e) {
+        message.setErrorResponse('Could not parse isolate id: $e');
+        return message.response;
+      }
+    }
+    var isolate = isolates[isolateId];
+    if (isolate == null) {
+      message.setErrorResponse('Cannot find isolate id: $isolateId');
+      return message.response;
+    }
+    return isolate.route(message);
+  }
+
+  Future<String> routeOld(Message message) {
     if (message.path.length == 0) {
       message.setErrorResponse('No path.');
       return message.response;
     }
     if (message.path[0] != 'isolates') {
       message.setErrorResponse('Path must begin with /isolates/');
       return message.response;
     }
     if (message.path.length < 2) {
       message.setErrorResponse('An isolate id must be provided');
@@ skipping 14 matching lines @@
     var isolate = isolates[isolateId];
     if (isolate == null) {
       message.setErrorResponse('Cannot find isolate id: $isolateId');
       return message.response;
     }
     // Consume '/isolates/isolateId'
     message.path.removeRange(0, 2);
     return isolate.route(message);
   }
 }