Add a WPT.

Differential Revision: https://phabricator.services.mozilla.com/D138779

bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1755332
gecko-commit: c89935b9bac58f6cfb994e061dcc395963d5cc93
gecko-reviewers: alwu

media-capabilities/decodingInfo.any.js

@@ -122,6 +122,29 @@ promise_test(t => {
   }));
 }, "Test that decodingInfo rejects if the video configuration contentType isn't of type video");
 
+promise_test(t => {
+  return promise_rejects_js(t, TypeError, navigator.mediaCapabilities.decodingInfo({
+    type: 'file',
+    video: {
+      contentType: 'application/ogg; codec=vorbis',
+      width: 800,
+      height: 600,
+      bitrate: 3000,
+      framerate: 24,
+    },
+  }));
+}, "Test that decodingInfo rejects if the video configuration contentType is of type audio");
+
+promise_test(t => {
+  return promise_rejects_js(t, TypeError, navigator.mediaCapabilities.decodingInfo({
+    type: 'file',
+    audio: {
+      contentType: 'application/ogg; codec=theora',
+      channels: 2,
+    },
+  }));
+}, "Test that decodingInfo rejects if the audio configuration contentType is of type video");
+
 promise_test(t => {
   return promise_rejects_js(t, TypeError, navigator.mediaCapabilities.decodingInfo({
     type: 'file',