Issue *24750: Switch all scrollbars in IDLE to ttk versions.

Where needed, add minimal tests to cover changes.

Lib/idlelib/idle_test/test_help.py

@@ -0,0 +1,34 @@
+'''Test idlelib.help.
+
+Coverage: 87%
+'''
+from idlelib import help
+from test.support import requires
+requires('gui')
+from os.path import abspath, dirname, join
+from tkinter import Tk
+import unittest
+
+class HelpFrameTest(unittest.TestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        "By itself, this tests that file parsed without exception."
+        cls.root = root = Tk()
+        root.withdraw()
+        helpfile = join(abspath(dirname(dirname(__file__))), 'help.html')
+        cls.frame = help.HelpFrame(root, helpfile)
+
+    @classmethod
+    def tearDownClass(cls):
+        del cls.frame
+        cls.root.update_idletasks()
+        cls.root.destroy()
+        del cls.root
+
+    def test_line1(self):
+        text = self.frame.text
+        self.assertEqual(text.get('1.0', '1.end'), ' IDLE ')
+
+if __name__ == '__main__':
+    unittest.main(verbosity=2)