Update nvda_chrome_tests.py to the latest pywinauto API.

Bug: 742592
Change-Id: Id572d0f9961a0c2795ae9abbc73696a05a7b94bf
Reviewed-on: https://chromium-review.googlesource.com/599627
Commit-Queue: Doug Turner <dougt@chromium.org>
Reviewed-by: Alice Boxhall <aboxhall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491913}

tools/accessibility/nvda/nvda_chrome_tests.py

@@ -113,8 +113,8 @@ class NvdaChromeTest(unittest.TestCase):
     print('NVDA pid: %d' % self._nvda_proc.pid)
 
     app = pywinauto.application.Application()
-    app.connect_(process = self._chrome_proc.pid)
-    self._pywinauto_window = app.top_window_()
+    app.connect(process = self._chrome_proc.pid)
+    self._pywinauto_window = app.top_window()
     self.last_nvda_log_line = 0;
 
   def tearDown(self):