[tools/perf] Fix JavaScript interpolation in action_runner calls

tools/perf/page_sets/indexeddb_endure_page.py

 # Copyright 2015 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.
 
 from telemetry.page import page as page_module
 from telemetry import story
 
 class IndexedDBEndurePage(page_module.Page):
 
   def __init__(self, subtest, page_set):
     super(IndexedDBEndurePage, self).__init__(
       url='file://indexeddb_perf/perf_test.html',
       page_set=page_set,
       name='indexeddb-endure-' + subtest)
     self._subtest = subtest
 
   def RunPageInteractions(self, action_runner):
-    # TODO(catapult:#3028): Fix interpolation of JavaScript values.
-    action_runner.ExecuteJavaScript('window.testFilter = "' +
-                                    self._subtest + '";')
+    action_runner.ExecuteJavaScript(
+        'window.testFilter = {{ subtest }};', subtest=self._subtest)
     with action_runner.CreateInteraction('Action_Test'):
       action_runner.ExecuteJavaScript('window.test();')
       action_runner.WaitForJavaScriptCondition(
           'window.done', timeout_in_seconds=600)
 
 class IndexedDBEndurePageSet(story.StorySet):
   """The IndexedDB Endurance page set.
 
   This page set exercises various common operations in IndexedDB.
   """
 
   def __init__(self):
     super(IndexedDBEndurePageSet, self).__init__()
     tests = [
       'testCreateAndDeleteDatabases',
       'testCreateAndDeleteDatabase',
       'testCreateKeysInStores',
       'testRandomReadsAndWritesWithoutIndex',
       'testRandomReadsAndWritesWithIndex',
       'testReadCacheWithoutIndex',
       'testReadCacheWithIndex',
       'testCreateAndDeleteIndex',
       'testWalkingMultipleCursors',
       'testCursorSeeksWithoutIndex',
       'testCursorSeeksWithIndex'
     ]
     for test in tests:
       self.AddStory(IndexedDBEndurePage(test, self))