[telemetry] Create BrowserTestCase to reuse the browser for browser_unittest.

tools/telemetry/telemetry/unittest/tab_test_case.py

Index: tools/telemetry/telemetry/unittest/tab_test_case.py
diff --git a/tools/telemetry/telemetry/unittest/tab_test_case.py b/tools/telemetry/telemetry/unittest/tab_test_case.py
index fbd0ee43e10fe8495f8088e23af4743846d3c268..81a198c6b7b5d03347b3fe9903d27c957c30d43b 100644
--- a/tools/telemetry/telemetry/unittest/tab_test_case.py
+++ b/tools/telemetry/telemetry/unittest/tab_test_case.py
@@ -2,44 +2,17 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import os
-import unittest
+from telemetry.unittest import browser_test_case
 
-from telemetry.core import browser_finder
-from telemetry.core import util
-from telemetry.unittest import options_for_unittests
-
-
-class TabTestCase(unittest.TestCase):
-  _extra_browser_args = []
 
+class TabTestCase(browser_test_case.BrowserTestCase):
   def __init__(self, *args):
     super(TabTestCase, self).__init__(*args)
-
     self._tab = None
-    self.test_file_path = None
-    self.test_url = None
-
-  @classmethod
-  def setUpClass(cls):
-    options = options_for_unittests.GetCopy()
-    cls.CustomizeBrowserOptions(options.browser_options)
-    if cls._extra_browser_args:
-      options.AppendExtraBrowserArgs(cls._extra_browser_args)
-
-    browser_to_create = browser_finder.FindBrowser(options)
-    if not browser_to_create:
-      raise Exception('No browser found, cannot continue test.')
-
-    cls._browser = None
-    try:
-      cls._browser = browser_to_create.Create()
-      cls._browser.Start()
-    except:
-      cls.tearDownClass()
-      raise
 
   def setUp(self):
+    super(TabTestCase, self).setUp()
+
     if self._browser.supports_tab_control:
       self._tab = self._browser.tabs.New()
       while len(self._browser.tabs) > 1:
@@ -52,23 +25,11 @@ class TabTestCase(unittest.TestCase):
     self._tab.Navigate('about:blank')
     self._tab.WaitForDocumentReadyStateToBeInteractiveOrBetter()
 
-  @classmethod
-  def tearDownClass(cls):
-    if cls._browser:
-      cls._browser.Close()
-
-  @classmethod
-  def CustomizeBrowserOptions(cls, options):
-    """Override to add test-specific options to the BrowserOptions object"""
-    pass
-
   def Navigate(self, filename, script_to_evaluate_on_commit=None):
     """Navigates |tab| to |filename| in the unittest data directory.
 
     Also sets up http server to point to the unittest data directory.
     """
-    self._browser.SetHTTPServerDirectories(util.GetUnittestDataDir())
-    self.test_file_path = os.path.join(util.GetUnittestDataDir(), filename)
-    self.test_url = self._browser.http_server.UrlOf(self.test_file_path)
-    self._tab.Navigate(self.test_url, script_to_evaluate_on_commit)
+    url = self.UrlOfUnittestFile(filename)
+    self._tab.Navigate(url, script_to_evaluate_on_commit)
     self._tab.WaitForDocumentReadyStateToBeComplete()