Bug 1319237 - Avoid reposition waiting if position is unchanged; r=maja_zf

When the requested window position is the same as the current position,
we should avoid the wait condition.

MozReview-Commit-ID: 3koG5BeOkFC

--HG--
extra : rebase_source : 028ad911ad387aa2b16051666c064e7d618fcbe4

testing/marionette/driver.js

@@ -1188,8 +1188,14 @@ GeckoDriver.prototype.setWindowPosition = function* (cmd, resp) {
   let orig = {screenX: win.screenX, screenY: win.screenY};
 
   win.moveTo(x, y);
-  yield wait.until(() => win.screenX != orig.screenX ||
-      win.screenY != orig.screenY);
+  yield wait.until((resolve, reject) => {
+    if ((x == win.screenX && y == win.screenY) ||
+      (win.screenX != orig.screenX || win.screenY != orig.screenY)) {
+      resolve();
+    } else {
+      reject();
+    }
+  });
 
   return this.curBrowser.position;
 };

testing/marionette/harness/marionette_harness/tests/unit/test_window_position.py

@@ -31,3 +31,10 @@ class TestWindowPosition(MarionetteTestCase):
         self.marionette.set_window_position(new_position["x"], new_position["y"])
         self.assertNotEqual(old_position["x"], new_position["x"])
         self.assertNotEqual(old_position["y"], new_position["y"])
+
+    def test_move_to_existing_position(self):
+        old_position = self.marionette.get_window_position()
+        self.marionette.set_window_position(old_position["x"], old_position["y"])
+        new_position = self.marionette.get_window_position()
+        self.assertEqual(old_position["x"], new_position["x"])
+        self.assertEqual(old_position["y"], new_position["y"])