Add suppression to test.dart for flaky content_shell crashes

tools/testing/dart/status_file_parser.dart

 // Copyright (c) 2012, 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 status_file_parser;
 
 import "dart:async";
 import "dart:convert" show LineSplitter, UTF8;
 import "dart:io";
 
@@ skipping 17 matching lines @@
   static Expectation MISSING_STATIC_WARNING = byName('MissingStaticWarning');
   static Expectation PUB_GET_ERROR = byName('PubGetError');
 
   // "meta expectations"
   static Expectation OK = byName('Ok');
   static Expectation SLOW = byName('Slow');
   static Expectation SKIP = byName('Skip');
   static Expectation SKIP_SLOW = byName('SkipSlow');
   static Expectation SKIP_BY_DESIGN = byName('SkipByDesign');
 
+  // Can be returned by the test runner to say the result should be ignored,
+  // and assumed to meet the expectations, due to an infrastructure failure.
+  // Do not place in status files.
+  static Expectation IGNORE = byName('Ignore');
+
   static Expectation byName(String name) {
     _initialize();
     name = name.toLowerCase();
     if (!_AllExpectations.containsKey(name)) {
       throw new Exception("Expectation.byName(name='$name'): Invalid name.");
     }
     return _AllExpectations[name];
   }
 
   // Keep a map of all possible Expectation objects, initialized lazily.
@@ skipping 22 matching lines @@
       build("MissingStaticWarning", group: fail);
       build("StaticWarning", group: fail);
 
       build("PubGetError", group: fail);
 
       var skip = build("Skip", isMetaExpectation: true);
       build("SkipByDesign", isMetaExpectation: true);
       build("SkipSlow", group: skip, isMetaExpectation: true);
       build("Ok", isMetaExpectation: true);
       build("Slow", isMetaExpectation: true);
+      build("Ignore");
     }
   }
 
   final String prettyName;
   final String name;
   final Expectation group;
   // Indicates whether this expectation cannot be a test outcome (i.e. it is a
   // "meta marker").
   final bool isMetaExpectation;
 
   Expectation._(prettyName,
       {Expectation this.group: null, bool this.isMetaExpectation: false})
       : prettyName = prettyName,
         name = prettyName.toLowerCase();
 
   bool canBeOutcomeOf(Expectation expectation) {
     Expectation outcome = this;
+    if (outcome == IGNORE) return true;
     while (outcome != null) {
       if (outcome == expectation) {
         return true;
       }
       outcome = outcome.group;
     }
     return false;
   }
 
   String toString() => prettyName;
@@ skipping 225 matching lines @@
         }
         regExps[i] = regExp;
       }
       _keyToRegExps[key] = regExps;
     });
 
     _regExpCache = null;
     _preprocessed = true;
   }
 }