Fix navigation to unittest files

tools/telemetry/telemetry/core/backends/chrome/inspector_page_unittest.py

 # Copyright 2013 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 import test
-from telemetry.core import util
 from telemetry.unittest import tab_test_case
 
 
 class InspectorPageTest(tab_test_case.TabTestCase):
   def __init__(self, *args):
     super(InspectorPageTest, self).__init__(*args)
 
   def setUp(self):
     super(InspectorPageTest, self).setUp()
-    self._browser.SetHTTPServerDirectories(util.GetUnittestDataDir())
 
   def testPageNavigateToNormalUrl(self):
-    self._tab.Navigate(self._browser.http_server.UrlOf('blank.html'))
-    self._tab.WaitForDocumentReadyStateToBeComplete()
+    self.Navigate('blank.html')
 
-  @test.Disabled('chromeos')
   def testCustomActionToNavigate(self):
-    self._tab.Navigate(
-      self._browser.http_server.UrlOf('page_with_link.html'))
-    self._tab.WaitForDocumentReadyStateToBeComplete()
+    self.Navigate('page_with_link.html')
     self.assertEquals(
         self._tab.EvaluateJavaScript('document.location.pathname;'),
         '/page_with_link.html')
 
     custom_action_called = [False]
     def CustomAction():
       custom_action_called[0] = True
       self._tab.ExecuteJavaScript('document.getElementById("clickme").click();')
 
     self._tab.PerformActionAndWaitForNavigate(CustomAction)
 
     self.assertTrue(custom_action_called[0])
     self.assertEquals(
         self._tab.EvaluateJavaScript('document.location.pathname;'),
         '/blank.html')
 
   def testGetCookieByName(self):
-    self._tab.Navigate(
-      self._browser.http_server.UrlOf('blank.html'))
-    self._tab.WaitForDocumentReadyStateToBeComplete()
+    self.Navigate('blank.html')
     self._tab.ExecuteJavaScript('document.cookie="foo=bar"')
     self.assertEquals(self._tab.GetCookieByName('foo'), 'bar')
 
   def testScriptToEvaluateOnCommit(self):
-    self._tab.Navigate(
-      self._browser.http_server.UrlOf('blank.html'),
-      script_to_evaluate_on_commit='var foo = "bar";')
+    self.Navigate('blank.html',
+                  script_to_evaluate_on_commit='var foo = "bar";')
     self._tab.WaitForDocumentReadyStateToBeComplete()
     self.assertEquals(self._tab.EvaluateJavaScript('foo'), 'bar')