update the analyzer and analysis server perf tags

pkg/analyzer/lib/src/generated/utilities_general.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.
 
 library analyzer.src.generated.utilities_general;
 
 import 'dart:collection';
 import 'dart:developer' show UserTag;
 
 export 'package:front_end/src/base/jenkins_smi_hash.dart' show JenkinsSmiHash;
@@ skipping 73 matching lines @@
 
   /**
    * Return the current [PerformanceTag] for the isolate.
    */
   static PerformanceTag get current => _PerformanceTagImpl.current;
 
   /**
    * Return the [PerformanceTag] that is initially current.  This is intended
    * to track time when the system is performing unknown operations.
    */
-  static PerformanceTag get UNKNOWN => _PerformanceTagImpl.UNKNOWN;
+  static PerformanceTag get unknown => _PerformanceTagImpl.unknown;
 
   /**
    * Create a [PerformanceTag] having the given [label].  A [UserTag] will also
    * be created, having the same [label], so that performance information can
    * be queried using the observatory.
    */
   factory PerformanceTag(String label) = _PerformanceTagImpl;
 
   /**
    * Return the total number of milliseconds that this [PerformanceTag] has
    * been the current [PerformanceTag] for the isolate.
    *
    * This call is safe even if this [PerformanceTag] is current.
    */
   int get elapsedMs;
 
   /**
    * Return the label for this [PerformanceTag].
    */
   String get label;
 
   /**
+   * Create a child tag of the current tag. The new tag's name will include the
+   * parent's name.
+   */
+  PerformanceTag createChild(String childTagName);
+
+  /**
    * Make this the current tag for the isolate, and return the previous tag.
    */
   PerformanceTag makeCurrent();
 
   /**
    * Make this the current tag for the isolate, run [f], and restore the
    * previous tag. Returns the result of invoking [f].
    */
   dynamic/*=E*/ makeCurrentWhile/*<E>*/(dynamic/*=E*/ f());
 
   /**
    * Reset the total time tracked by all [PerformanceTag]s to zero.
    */
   static void reset() {
     for (_PerformanceTagImpl tag in _PerformanceTagImpl.all) {
       tag.stopwatch.reset();
     }
   }
 }
 
 class _PerformanceTagImpl implements PerformanceTag {
   /**
    * The current performance tag for the isolate.
    */
-  static _PerformanceTagImpl current = UNKNOWN;
+  static _PerformanceTagImpl current = unknown;
 
-  static final _PerformanceTagImpl UNKNOWN = new _PerformanceTagImpl('unknown');
+  static final _PerformanceTagImpl unknown = new _PerformanceTagImpl('unknown');
 
   /**
    * A list of all performance tags that have been created so far.
    */
   static List<_PerformanceTagImpl> all = <_PerformanceTagImpl>[];
 
   /**
    * The [UserTag] associated with this [PerformanceTag].
    */
   final UserTag userTag;
@@ skipping 10 matching lines @@
     all.add(this);
   }
 
   @override
   int get elapsedMs => stopwatch.elapsedMilliseconds;
 
   @override
   String get label => userTag.label;
 
   @override
+  PerformanceTag createChild(String childTagName) {
+    return new _PerformanceTagImpl('$label.$childTagName');
+  }
+
+  @override
   PerformanceTag makeCurrent() {
     if (identical(this, current)) {
       return current;
     }
     _PerformanceTagImpl previous = current;
     previous.stopwatch.stop();
     stopwatch.start();
     current = this;
     userTag.makeCurrent();
     return previous;
   }
 
   dynamic/*=E*/ makeCurrentWhile/*<E>*/(dynamic/*=E*/ f()) {
     PerformanceTag prevTag = makeCurrent();
     try {
       return f();
     } finally {
       prevTag.makeCurrent();
     }
   }
 }