Fix exception when running Sheriff-o-Matic tests.

Exception is caused by embedded-flakiness-dashboard. The iframe needs to
be added to the DOM to expose the contentWindow property.

By adding captureConsole: true to karma.conf.js, we will also see these
errors in the karma test runner in the future.

BUG=404415
R=ojan@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/484753002

git-svn-id: svn://svn.chromium.org/blink/trunk@180485 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Tools/GardeningServer/karma.conf.js

@@ -17,7 +17,8 @@ module.exports = function(config) {
         ui: 'bdd',
         checkLeaks: true,
         globals: ['net']
-      }
+      },
+      captureConsole: true
     },
 
     // list of files / patterns to load in the browser

third_party/WebKit/Tools/GardeningServer/ui/test/ct-commit-list-tests.html

@@ -30,11 +30,11 @@ describe('ct-commit-list', function() {
             expanded: false }
       ];
 
-      var CommitList = Object.create(Object);
-      CommitList.prototype.repositories = function() {
-        return repos;
+      list.commitList = {
+        repositories: function() {
+          return repos;
+        }
       };
-      list.commitList = CommitList;
 
       setTimeout(done);
     });

third_party/WebKit/Tools/GardeningServer/ui/test/ct-results-panel-tests.html

@@ -97,12 +97,19 @@ describe('ct-results-panel', function() {
 
   beforeEach(function(done) {
     panel = document.createElement('ct-results-panel');
+    panel.hidden = true;
+    document.body.appendChild(panel);
+
     if (failures)
       panel.failures = failures;
 
     setTimeout(done);
   });
 
+  afterEach(function() {
+    document.body.removeChild(panel);
+  });
+
   describe('empty', function() {
     before(function() {
       failures = undefined;