Move base_dir to user_story_set, remove file_path.

tools/telemetry/telemetry/user_story/user_story_set_unittest.py

Index: tools/telemetry/telemetry/user_story/user_story_set_unittest.py
diff --git a/tools/telemetry/telemetry/user_story/user_story_set_unittest.py b/tools/telemetry/telemetry/user_story/user_story_set_unittest.py
index 9b381d6c7975088bc5df6391eaa0f7f7c0360f3a..e13f8d216da54e545c867f6310d2220efcb6d5ee 100644
--- a/tools/telemetry/telemetry/user_story/user_story_set_unittest.py
+++ b/tools/telemetry/telemetry/user_story/user_story_set_unittest.py
@@ -43,6 +43,11 @@ class UserStorySetTest(unittest.TestCase):
     self.assertTrue(os.path.isdir(base_dir))
     self.assertEqual(base_dir, os.path.dirname(__file__))
 
+  def testFilePath(self):
+      uss = UserStorySetFoo()
+      self.assertEqual(os.path.abspath(__file__).replace('.pyc', '.py'),
+                       uss.file_path)
+
   def testCloudBucket(self):
     blank_uss = user_story_set.UserStorySet()
     self.assertEqual(blank_uss.bucket, None)