Bug 1670800: Add accessibility tests for non-plugin object and embed elements r=eeejay

<object> and <embed> elements can handle a number of media-like resources, like images, videos, audio, PDFs.  This patch adds tests for all but video.  See bug 1670803 for video tests.

Differential Revision: https://phabricator.services.mozilla.com/D93273

accessible/tests/mochitest/a11y.ini

@@ -1,6 +1,7 @@
 [DEFAULT]
 support-files =
   ../../../dom/media/test/bug461281.ogg
+  ../../../dom/security/test/csp/dummy.pdf
   dumbfile.zip
   formimage.png
   letters.gif

accessible/tests/mochitest/elm/a11y.ini

@@ -3,7 +3,8 @@ support-files =
   !/accessible/tests/mochitest/*.js
   !/accessible/tests/mochitest/moz.png
   !/dom/media/test/bug461281.ogg
-
+  !/dom/security/test/csp/dummy.pdf
+  
 [test_HTMLSpec.html]
 [test_figure.html]
 [test_listbox.xhtml]

accessible/tests/mochitest/elm/test_HTMLSpec.html

@@ -459,7 +459,7 @@
       testElm("em_container", obj);
 
       // ////////////////////////////////////////////////////////////////////////
-      // HTML:embed (windowless and windowed plugins)
+      // HTML:embed (windowless/windowed plugins and media)
 
       if (WIN) {
         obj = {
@@ -476,6 +476,29 @@
         testElm("embed_plugin_windowed", obj);
       }
 
+      obj = {
+        role: ROLE_GRAPHIC,
+        interfaces: [ nsIAccessibleImage ],
+      };
+      testElm("embed_png", obj);
+
+      obj = {
+        INTERNAL_FRAME: [ {
+          DOCUMENT: [ {
+            role: ROLE_PARAGRAPH,
+          } ],
+        } ],
+      };
+      testElm("embed_html", obj);
+
+      obj = {
+        INTERNAL_FRAME: [ {
+          DOCUMENT: [ {
+          } ],
+        } ],
+      };
+      testElm("embed_pdf", obj);
+
       // ////////////////////////////////////////////////////////////////////////
       // HTML:fieldset and HTML:legend
 
@@ -1108,7 +1131,7 @@
       testElm("nav", obj);
 
       // ////////////////////////////////////////////////////////////////////////
-      // HTML:object (windowless and windowed plugins) and HTML:param
+      // HTML:object (windowless/windowed plugins and media) and HTML:param
 
       if (WIN) {
         obj = {
@@ -1125,6 +1148,29 @@
         testElm("object_plugin_windowed", obj);
       }
 
+      obj = {
+        role: ROLE_GRAPHIC,
+        interfaces: [ nsIAccessibleImage ],
+      };
+      testElm("object_png", obj);
+
+      obj = {
+        INTERNAL_FRAME: [ {
+          DOCUMENT: [ {
+            role: ROLE_PARAGRAPH,
+          } ],
+        } ],
+      };
+      testElm("object_html", obj);
+
+      obj = {
+        INTERNAL_FRAME: [ {
+          DOCUMENT: [ {
+          } ],
+        } ],
+      };
+      testElm("object_pdf", obj);
+
       // ////////////////////////////////////////////////////////////////////////
       // HTML:select, HTML:optgroup and HTML:option
 
@@ -1578,6 +1624,16 @@
   <embed id="embed_plugin_windowed" type="application/x-test" wmode="window"
          width="300" height="300"></embed>
 
+  <embed id="embed_png" type="image/png" src="../moz.png"
+         width="300" height="300">
+  </embed>
+  <embed id="embed_html" type="text/html" src="../longdesc_src.html"
+         width="300" height="300">
+  </embed>
+  <embed id="embed_pdf" type="application/pdf" src="../dummy.pdf"
+         width="300" height="300">
+  </embed>
+
   <fieldset id="fieldset">
     <legend id="legend">legend</legend>
     <input />
@@ -1867,6 +1923,16 @@
   <object id="object_plugin_windowed" type="application/x-test" wmode="window"
          width="300" height="300"></object>
 
+  <object id="object_png" type="image/png" data="../moz.png"
+         width="300" height="300">
+  </object>
+  <object id="object_html" type="text/html" data="../longdesc_src.html"
+         width="300" height="300">
+  </object>
+  <object id="object_pdf" type="application/pdf" data="../dummy.pdf"
+         width="300" height="300">
+  </object>
+
   <select id="select_listbox" size="4">
     <optgroup label="Colors">
       <option>Red</option>