Add a "Link Bug" button to associate a bug with a failure

Tools/GardeningServer/model/ct-failure-group.html

 <!--
 Copyright 2014 The Chromium Authors. All rights reserved.
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 -->
 
 <link rel="import" href="ct-commit-list.html">
 
 <script>
 function CTFailureGroup(key, failures, annotation) {
   this.key = key;
   this.failures = failures;
-  this.annotation = annotation || {};
+  this._annotation = annotation || {};
   this._computeProperties();
 }
 
 CTFailureGroup.prototype.snoozeUntil = function(time) {
   return this._annotate({
     snoozeTime: time,
   });
 };
 
 CTFailureGroup.prototype.unsnooze = function() {
   return this._annotate({
     snoozeTime: undefined,
   });
 };
 
 CTFailureGroup.prototype.commitList = function(commits) {
   return new CTCommitList(this, commits);
 };
 
+CTFailureGroup.prototype.setBug = function(bug) {
+  if (/^[0-9]+$/.test(bug))
+    bug = 'http://crbug.com/' + bug;
+  return this._annotate({
+    bug: bug,
+  });
+};
+
 CTFailureGroup.prototype._computeProperties = function() {
-  this.isSnoozed = Date.now() < this.annotation.snoozeTime;
+  this.isSnoozed = Date.now() < this._annotation.snoozeTime;
   if (this.isSnoozed) {
     this.category = 'snoozed';
   } else {
     // FIXME: crbug.com/400397 Split into: Whole step failure, Tree closer, Test failure, Flaky tests
     this.category = 'default';
   }
+
+  this.bug = this._annotation.bug;
+  if (this.bug !== undefined)
+    this.bugLabel = 'Bug ' + /([0-9]{3,})/.exec(this.bug)[0];
+  else
+    this.bugLabel = undefined;
 };
 
 CTFailureGroup.prototype._annotate = function(newAnnotation) {
   // FIXME: Post the new annotation to frontend rather than storing locally.
   return CTFailureGroup.fetchAnnotations().then(function(annotations) {
     var annotation = annotations[this.key] || {};
 
     Object.keys(newAnnotation, function(key, value) {
       if (value === 'undefined') {
         delete annotation[key];
       } else {
         annotation[key] = value;
       }
     });
 
     if (Object.size(annotation) == 0) {
       delete annotations[this.key];
     } else {
       annotations[this.key] = annotation;
     }
 
     localStorage.CTFailureGroupAnnotations = JSON.stringify(annotations);
 
-    this.annotation = annotation;
+    this._annotation = annotation;
     this._computeProperties();
   }.bind(this));
 };
 
 CTFailureGroup.fetchAnnotations = function() {
   // FIXME: Fetch annotations from frontend.
   var stored = localStorage.CTFailureGroupAnnotations;
   var annotations = stored ? JSON.parse(stored) : {};
   return Promise.resolve(annotations);
 };
 </script>