Fix many warnings/errors when building Observatory

runtime/observatory/lib/src/service/object.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.
 
 part of service;
 
 // Some value smaller than the object ring, so requesting a large array
 // doesn't result in an expired ref because the elements lapped it in the
 // object ring.
 const int kDefaultFieldLimit = 100;
@@ skipping 423 matching lines @@
     size = map['size'];
   }
 }
 
 class RetainingObject implements M.RetainingObject {
   int get retainedSize => object.retainedSize;
   final HeapObject object;
   RetainingObject(this.object);
 }
 
-abstract class ServiceObjectOwner extends ServiceObject {
+abstract class ServiceObjectOwner extends ServiceObject
+    implements M.ServiceObjectOwner {
   /// Creates an empty [ServiceObjectOwner].
   ServiceObjectOwner._empty(ServiceObjectOwner owner) : super._empty(owner);
 
   /// Builds a [ServiceObject] corresponding to the [id] from [map].
   /// The result may come from the cache.  The result will not necessarily
   /// be [loaded].
   ServiceObject getFromMap(Map map);
+
+  Future<M.Object> invokeRpc(String method, Map params);
 }
 
 abstract class Location implements M.Location {
   Script get script;
   int get tokenPos;
 }
 
 /// A [SourceLocation] represents a location or range in the source code.
 class SourceLocation extends ServiceObject
     implements Location, M.SourceLocation {
@@ skipping 363 matching lines @@
             "Response is missing the 'type' field", map);
         return new Future.error(exception);
       }
       return new Future.value(map);
     }).catchError((e) {
       // Errors pass through.
       return new Future.error(e);
     });
   }
 
-  Future<ServiceObject> invokeRpc(String method, Map params) {
+  Future<dynamic> invokeRpc(String method, Map params) {
     return invokeRpcNoUpgrade(method, params).then((Map response) {
       var obj = new ServiceObject._fromMap(this, response);
       if ((obj != null) && obj.canCache) {
         String objId = obj.id;
         _cache.putIfAbsent(objId, () => obj);
       }
       return obj;
     }).catchError((e) {
       return new Future.error(e);
     });
@@ skipping 612 matching lines @@
       _cache[mapId] = obj;
     }
     return obj;
   }
 
   Future<Map> invokeRpcNoUpgrade(String method, Map params) {
     params['isolateId'] = id;
     return vm.invokeRpcNoUpgrade(method, params);
   }
 
-  Future<ServiceObject> invokeRpc(String method, Map params) {
+  Future<dynamic> invokeRpc(String method, Map params) {
     return invokeRpcNoUpgrade(method, params).then((Map response) {
       return getFromMap(response);
     });
   }
 
   Future<ServiceObject> getObject(String objectId,
       {bool reload: true, int count: kDefaultFieldLimit}) {
     assert(objectId != null && objectId != '');
     var obj = _cache[objectId];
     if (obj != null) {
@@ skipping 3146 matching lines @@
     var v = list[i];
     if ((v is Map) && _isServiceMap(v)) {
       list[i] = owner.getFromMap(v);
     } else if (v is List) {
       _upgradeList(v, owner);
     } else if (v is Map) {
       _upgradeMap(v, owner);
     }
   }
 }