Bug 1364594: Exit fullscreen when Set Window Rect is invoked. r=ato

If the browser is in fullscreen mode and Set Window Rect is called
we need to exit fullscreen mode and then continue to manipulate the
browser.

As described in https://w3c.github.io/webdriver/webdriver-spec.html#set-window-rect
Step 10

MozReview-Commit-ID: 5ixhGOXVBE4

--HG--
extra : rebase_source : be2b8b6da5cf78c6263502a6cb422e2de81c742d

testing/marionette/driver.js

@@ -1370,6 +1370,10 @@ GeckoDriver.prototype.setWindowRect = function* (cmd, resp) {
 
   let {x, y, width, height} = cmd.parameters;
 
+  if (win.windowState == win.STATE_FULLSCREEN) {
+    win.document.exitFullscreen();
+  }
+
   if (height != null && width != null) {
     assert.positiveInteger(height);
     assert.positiveInteger(width);

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

@@ -36,18 +36,16 @@ class TestWindowMaximize(MarionetteTestCase):
         else:
             delta = 8
 
-        self.assertAlmostEqual(
-            actual["width"], self.max["width"],
-            delta=delta,
-            msg="Window width is not within {} px of availWidth: "
-                "current width {} and max width {}"
-                .format(delta, actual["width"], self.max["width"]))
-        self.assertAlmostEqual(
+        self.assertGreaterEqual(
+            actual["width"], self.max["width"] - delta,
+            msg="Window width is not within {delta} px of availWidth: "
+                "current width {expected} should be greater than max width {max}"
+                .format(delta=delta, expected=actual["width"], max=self.max["width"] - delta))
+        self.assertGreaterEqual(
             actual["height"], self.max["height"],
-            delta=delta,
-            msg="Window height is not within {} px of availHeight, "
-                "current height {} and max height {}"
-                .format(delta, actual["height"], self.max["height"]))
+            msg="Window height is not within {delta} px of availHeight: "
+                "current height {expected} should be greater than max width {max}"
+                .format(delta=delta, expected=actual["height"], max=self.max["height"] - delta))
 
     def assert_window_restored(self, actual):
         self.assertEqual(self.original_size["width"], actual["width"])

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

@@ -121,8 +121,8 @@ class TestSize(MarionetteTestCase):
         # so reset to original size minus 1 pixel width
         start_size = self.marionette.window_size
         if start_size["width"] == self.max["width"] and start_size["height"] == self.max["height"]:
-            start_size["width"] -= 1
-            start_size["height"] -= 1
+            start_size["width"] -= 10
+            start_size["height"] -= 10
         self.marionette.set_window_size(start_size["width"], start_size["height"])
 
         self.original_size = self.marionette.window_size
@@ -130,6 +130,9 @@ class TestSize(MarionetteTestCase):
     def tearDown(self):
         self.marionette.set_window_size(
             self.original_size["width"], self.original_size["height"])
+        is_fullscreen = self.marionette.execute_script("return document.fullscreenElement;", sandbox=None)
+        if is_fullscreen:
+            self.marionette.fullscreen()
         super(MarionetteTestCase, self).tearDown()
 
     def test_get_types(self):
@@ -190,3 +193,13 @@ class TestSize(MarionetteTestCase):
                                                  height=self.max["height"])
         self.assertEqual(result["width"], self.max["width"])
         self.assertEqual(result["height"], self.max["height"])
+
+    def test_resize_while_fullscreen(self):
+        self.marionette.fullscreen()
+        result = self.marionette.set_window_rect(width=self.max["width"] - 100,
+                                                 height=self.max["height"] - 100)
+
+        self.assertTrue(self.marionette.execute_script("return window.fullscreenElement == null",
+                                                        sandbox=None))
+        self.assertEqual(result["width"], self.max["width"] - 100)
+        self.assertEqual(result["height"], self.max["height"] - 100)