Bug 1111815 - adding accessibility checks for isElementDisplayed. r=dburns

---
 .../marionette/tests/unit/test_accessibility.py       | 19 +++++++++++++++++++
 .../client/marionette/www/test_accessibility.html     |  1 +
 testing/marionette/marionette-listener.js             |  4 +++-
 3 files changed, 23 insertions(+), 1 deletion(-)

testing/marionette/client/marionette/tests/unit/test_accessibility.py

@@ -48,6 +48,13 @@ class TestAccessibility(MarionetteTestCase):
         "button10"
     ]
 
+    displayed_elementIDs = [
+        "button1", "button2", "button3", "button4", "button5", "button6",
+        "button9", "no_accessible_but_displayed"
+    ]
+
+    displayed_but_a11y_hidden_elementIDs = ["button7", "button8"]
+
     def run_element_test(self, ids, testFn):
         for id in ids:
             element = self.marionette.find_element("id", id)
@@ -107,3 +114,15 @@ class TestAccessibility(MarionetteTestCase):
         self.run_element_test(self.falsy_elements,
                               lambda button: self.assertRaises(ElementNotVisibleException,
                                                                button.click))
+
+    def test_element_visible_but_not_visible_to_accessbility(self):
+        self.setup_accessibility()
+        # Elements are displayed but hidden from accessibility API
+        self.run_element_test(self.displayed_but_a11y_hidden_elementIDs,
+                              lambda element: self.assertRaises(ElementNotAccessibleException,
+                                                                element.is_displayed))
+
+    def test_element_is_visible_to_accessibility(self):
+        self.setup_accessibility()
+        # No exception should be raised
+        self.run_element_test(self.displayed_elementIDs, lambda element: element.is_displayed())

testing/marionette/client/marionette/www/test_accessibility.html

@@ -28,6 +28,7 @@
   <button id="button10" style="visibility:hidden;">
     button10
   </button>
+  <span id="no_accessible_but_displayed">I have no accessible object</span>
   <script>
       document.getElementById('button5').addEventListener('click', function() {
         // A pseudo button that has a listener but is missing button semantics.

testing/marionette/marionette-listener.js

@@ -1551,7 +1551,9 @@ function isElementDisplayed(msg) {
   let command_id = msg.json.command_id;
   try {
     let el = elementManager.getKnownElement(msg.json.id, curFrame);
-    sendResponse({value: utils.isElementDisplayed(el)}, command_id);
+    let displayed = utils.isElementDisplayed(el);
+    checkVisibleAccessibility(accessibility.getAccessibleObject(el), displayed);
+    sendResponse({value: displayed}, command_id);
   }
   catch (e) {
     sendError(e.message, e.code, e.stack, command_id);