Use failure.tree field provided by the builder_alerts generator

Tools/GardeningServer/model/test/ct-failures-tests.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-failures.html">
 
 <link rel="import" href="../../lib/network-simulator.html">
 <link rel="import" href="../ct-commit-list.html">
@@ skipping 57 matching lines @@
     });
   });
 
   describe('._mungeAlerts', function() {
     it('puts alerts into a standard format', function() {
       var analyzer = new CTFailures(new CTCommitList(undefined, []));
       var alerts = [
         {
           reason: 'reason',
           master_url: 'https://build.chromium.org/p/chromium.webkit',
+          tree: 'blink',
         },
         {
           reason: 'reason:type',
           master_url: 'https://build.chromium.org/p/chromium.chrome',
+          tree: 'chromium',
         },
         {
           master_url: 'https://build.chromium.org/p/chromium.gpu',
+          tree: 'chromium',
         },
         {
           reason: 'reason:type',
           failureType: 'actual_type',
+          tree: undefined,
         },
       ];
       analyzer._mungeAlerts(alerts);
       assert.lengthOf(alerts, 4);
       assert.deepEqual(alerts[0], {
         reason: 'reason',
         failureType: 'FAIL',
         master_url: 'https://build.chromium.org/p/chromium.webkit',
         tree: 'blink',
       });
@@ skipping 166 matching lines @@
               reason: null,
               failing_revisions: {
                 v8: 50,
                 chromium: 101,
                 nacl: 50,
                 blink: 50
               },
               builder_name: "Linux Tests (dbg)(1)",
               key: "f1",
               step_name: "compile",
-              tree_name: null,
+              tree: 'chromium',
               passing_revisions: {
                 v8: 50,
                 chromium: 99,
                 nacl: 50,
                 blink: 50
               },
               would_close_tree: true
             },
           ],
         }
@@ skipping 69 matching lines @@
                      'tree_2': {should_alert: false, should_appear: false}},
            'key_2': {'tree_3': {should_alert: false, should_appear: false},
                      'tree_4': {should_alert: true, should_appear: true}}});
       analyzer.failures['trooper'].forEach(function(failure) {
         assert(failure.data.data.should_appear);
       });
       assert(analyzer.failures['trooper'].length == 2);
     });
   });
 
+  describe('processFailuresForRangeGroup', function() {
+    it('should use tree name from json', function() {
+      var analyzer = new CTFailures(null);
+
+      var annotations = Promise.resolve({
+        'test-key': 'test-annotation',
+      })
+      var range_groups = {
+        'failure_keys': ['test-key'],
+        'likely_revisions': []
+      }
+      var alertsByKey = {
+          'test-key': {
+              'key': 'test-key',
+              'step_name': 'bot_update',
+              'tree': 'test-tree',
+              'builder_name': 'Linux',
+              'last_failing_build': 1234,
+              'failing_build': 1234,
+              'master_url': 'http://build.chromium.org/p/chromium',
+              'failing_build_count': 1,
+              'reason': 'test-reason',
+          }
+      }
+      var newFailures = {}
+
+      analyzer._processFailuresForRangeGroup(newFailures, range_groups, alertsByKey, annotations)
+      assert.ok('test-tree' in newFailures)
+      assert.notOk('chromium' in newFailures)
+    });
+  });
+
 });
 
 })()
 </script>