abstract qt away from trezor

plugins/trezor/qt.py

@@ -125,7 +125,7 @@ class QtHandler(QtHandlerBase):
         self.done.wait()
         data = self.matrix_dialog.data
         if data == 'x':
-            self.close_matrix_dialog_signal.emit()
+            self.close_matrix_dialog()
         return data
 
     def _close_matrix_dialog(self):
@@ -133,6 +133,9 @@ class QtHandler(QtHandlerBase):
             self.matrix_dialog.accept()
             self.matrix_dialog = None
 
+    def close_matrix_dialog(self):
+        self.close_matrix_dialog_signal.emit()
+
     def pin_dialog(self, msg):
         # Needed e.g. when resetting a device
         self.clear_dialog()