Implement function entry breakpoints in Observatory debugger.

runtime/observatory/lib/src/cli/command.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.
 
 part of cli;
 
 // Splits a line into a list of string args.
 List<String> _splitLine(String line) {
   var args = line.split(' ').where((arg) {
       return arg != ' ' && arg != '';
@@ skipping 172 matching lines @@
 
 // A node in the command tree.
 abstract class Command extends _CommandBase {
   Command(this.name, List<Command> children) : super(children);
 
   final String name;
   String get fullName {
     if (_parent is RootCommand) {
       return name;
     } else {
-      return '${_parent.fullName} $name';
+      Command parent = _parent;

[Cutch, 2015/02/13 19:30:52]

var parent = _parent;

[turnidge, 2015/02/13 22:37:19]

Acknowledged.

+      return '${parent.fullName} $name';
     }
   }
 
   toString() => 'Command(${name})';
 }