[Autotest] make touch tests ignore -cheets in platform names.

If the platform name ends with -cheets, remove that suffix.

BUG=chromium:616323
TEST=ran on -cheets device

Change-Id: If972c6b1ed77f450457dd59adeabb08e92f9eb26
Reviewed-on: https://chromium-review.googlesource.com/356801
Commit-Ready: Katherine Threlkeld <kathrelkeld@chromium.org>
Tested-by: Katherine Threlkeld <kathrelkeld@chromium.org>
Reviewed-by: Tien Chang <tienchang@chromium.org>
diff --git a/client/cros/touch_playback_test_base.py b/client/cros/touch_playback_test_base.py
index cbe74d5..792fa19 100644
--- a/client/cros/touch_playback_test_base.py
+++ b/client/cros/touch_playback_test_base.py
@@ -58,6 +58,8 @@
         self._autotest_ext = None
         self._has_inputcontrol = os.path.isfile(self._INPUTCONTROL)
         self._platform = utils.get_board()
+        if 'cheets' in self._platform:
+            self._platform = self._platform[:-len('-cheets')]
 
 
     def _find_test_files(self, input_type, gestures):
@@ -446,10 +448,7 @@
         @param is_vertical: True for vertical scrolling; False for horizontal.
 
         """
-        if is_vertical:
-            axis = 'y'
-        else:
-            axis = 'x'
+        axis = 'y' if is_vertical else 'x'
         return self._tab.EvaluateJavaScript('netScrollDelta.%s' % axis)