Switch to using SourceLocation universally in service protocol.

runtime/observatory/tests/service/get_stack_rpc_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';
 import 'dart:isolate' as isolate;
@@ skipping 31 matching lines @@
   expect(isolate.pauseEvent.kind, equals(ServiceEvent.kPauseBreakpoint));
 },
 
 // Get stack
 (Isolate isolate) async {
   var stack = await isolate.getStack();
   expect(stack.type, equals('Stack'));
 
   // Sanity check.
   expect(stack['frames'].length, greaterThanOrEqualTo(1));
-  Script script = stack['frames'][0]['script'];
-  expect(script.tokenToLine(stack['frames'][0]['tokenPos']),
+  Script script = stack['frames'][0].location.script;
+  expect(script.tokenToLine(stack['frames'][0].location.tokenPos),
          equals(stoppedAtLine));
 
   // Iterate over frames.
   var frameDepth = 0;
   for (var frame in stack['frames']) {
     print('checking frame $frameDepth');
     expect(frame.type, equals('Frame'));
-    expect(frame['index'], equals(frameDepth++));
-    expect(frame['code'].type, equals('Code'));
-    expect(frame['function'].type, equals('Function'));
-    expect(frame['script'].type, equals('Script'));
-    expect(frame['tokenPos'], isNotNull);
+    expect(frame.index, equals(frameDepth++));
+    expect(frame.code.type, equals('Code'));
+    expect(frame.function.type, equals('Function'));
+    expect(frame.location.type, equals('SourceLocation'));
   }
 
   // Sanity check.
   expect(stack['messages'].length, greaterThanOrEqualTo(1));
 
   // Iterate over messages.
   var messageDepth = 0;
   // objectId of message to be handled by msgHandler.
   var msgHandlerObjectId;
   for (var message in stack['messages']) {
     print('checking message $messageDepth');
-    expect(message['index'], equals(messageDepth++));
-    expect(message['name'], isNotNull);
-    expect(message['size'], greaterThanOrEqualTo(1));
-    expect(message['_priority'], isNotNull);
-    expect(message['_destinationPort'], isNotNull);
-    expect(message['handlerFunction'].type, equals('Function'));
-    if (message['handlerFunction'].name.contains('msgHandler')) {
-      msgHandlerObjectId = message['messageObjectId'];
+    expect(message.index, equals(messageDepth++));
+    expect(message.size, greaterThanOrEqualTo(1));
+    expect(message.handler.type, equals('Function'));
+    expect(message.location.type, equals('SourceLocation'));
+    if (message.handler.name.contains('msgHandler')) {
+      msgHandlerObjectId = message.messageObjectId;
     }
   }
   expect(msgHandlerObjectId, isNotNull);
 
   // Get object.
   var object = await isolate.getObject(msgHandlerObjectId);
   expect(object.valueAsString, equals('34'));
 }
 
 ];
 
 main(args) => runIsolateTests(args, tests, testeeBefore: startTimer);