Switch to using SourceLocation universally in service protocol.

runtime/observatory/tests/service/eval_test.dart

 // Copyright (c) 2015, 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.
 // VMOptions=--compile-all --error_on_bad_type --error_on_bad_override
 
 import 'package:observatory/service_io.dart';
 import 'package:unittest/unittest.dart';
 import 'test_helper.dart';
 import 'dart:async';
 
@@ skipping 38 matching lines @@
       });
     });
 },
 
 // Evaluate against library, class, and instance.
 (Isolate isolate) {
   return isolate.getStack().then((ServiceMap stack) {
       // Make sure we are in the right place.
       expect(stack.type, equals('Stack'));
       expect(stack['frames'].length, greaterThanOrEqualTo(2));
-      expect(stack['frames'][0]['function'].name, equals('printValue'));
-      expect(stack['frames'][0]['function'].dartOwner.name, equals('MyClass'));
+      expect(stack['frames'][0].function.name, equals('printValue'));
+      expect(stack['frames'][0].function.dartOwner.name, equals('MyClass'));
 
       var lib = isolate.rootLibrary;
-      var cls = stack['frames'][0]['function'].dartOwner;
-      var instance = stack['frames'][0]['vars'][0]['value'];
+      var cls = stack['frames'][0].function.dartOwner;
+      var instance = stack['frames'][0].variables[0]['value'];
 
       List evals = [];
       evals.add(lib.evaluate('globalVar + 5').then((result) {
             print(result);
             expect(result.valueAsString, equals('105'));
           }));
       evals.add(lib.evaluate('globalVar + staticVar + 5').then((result) {
             expect(result.type, equals('Error'));
           }));
       evals.add(cls.evaluate('globalVar + staticVar + 5').then((result) {
@@ skipping 10 matching lines @@
       evals.add(instance.evaluate('this + frog').then((result) {
             expect(result.type, equals('Error'));
           }));
       return Future.wait(evals);
   });
 },
 
 ];
 
 main(args) => runIsolateTests(args, tests, testeeConcurrent: testFunction);