Fixes to patch files necessary to use the analyzer

sdk/lib/developer/profiler.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 dart.developer;
 
 /// A UserTag can be used to group samples in the Observatory profiler.
 abstract class UserTag {
   /// The maximum number of UserTag instances that can be created by a program.
   static const MAX_USER_TAGS = 64;
 
-  factory UserTag(String label) => new _FakeUserTag(label);
+  external factory UserTag(String label);
 
   /// Label of [this].
   String get label;
 
   /// Make [this] the current tag for the isolate. Returns the current tag
   /// before setting.
   UserTag makeCurrent();
 
   /// The default [UserTag] with label 'Default'.
-  static UserTag get defaultTag => _FakeUserTag._defaultTag;
+  external static UserTag get defaultTag;
 }
 
-// This is a fake implementation of UserTag so that code can compile and run
-// in dart2js.
-class _FakeUserTag implements UserTag {
-  static Map _instances = {};
-
-  _FakeUserTag.real(this.label);
-
-  factory _FakeUserTag(String label) {
-    // Canonicalize by name.
-    var existingTag = _instances[label];
-    if (existingTag != null) {
-      return existingTag;
-    }
-    // Throw an exception if we've reached the maximum number of user tags.
-    if (_instances.length == UserTag.MAX_USER_TAGS) {
-      throw new UnsupportedError(
-          'UserTag instance limit (${UserTag.MAX_USER_TAGS}) reached.');
-    }
-    // Create a new instance and add it to the instance map.
-    var instance = new _FakeUserTag.real(label);
-    _instances[label] = instance;
-    return instance;
-  }
-
-  final String label;
-
-  UserTag makeCurrent() {
-    var old = _currentTag;
-    _currentTag = this;
-    return old;
-  }
-
-  static final UserTag _defaultTag = new _FakeUserTag('Default');
-}
-
-var _currentTag = _FakeUserTag._defaultTag;
-
 /// Returns the current [UserTag] for the isolate.
-UserTag getCurrentTag() {
-  return _currentTag;
-}
+external UserTag getCurrentTag();
 
 /// Abstract [Metric] class. Metric names must be unique, are hierarchical,
 /// and use periods as separators. For example, 'a.b.c'. Uniqueness is only
 /// enforced when a Metric is registered. The name of a metric cannot contain
 /// the slash ('/') character.
 abstract class Metric {
   /// [name] of this metric.
   final String name;
   /// [description] of this metric.
   final String description;
@@ skipping 112 matching lines @@
     for (var metric in _metrics.values) {
       metrics.add(metric._toJSON());
     }
     var map = {
       'type': 'MetricList',
       'metrics': metrics,
     };
     return JSON.encode(map);
   }
 }