Bug 1147699 - Part 6: Add a test for FetchEvent.request.context when intercepting a video element load; r=nsm

Note that currently our implementation incorrectly reflects this as
'audio'.  This will be fixed later.

dom/workers/test/serviceworkers/fetch/context/context_test.js

@@ -20,6 +20,11 @@ self.addEventListener("fetch", function(event) {
     if (event.request.context == "audio") {
       event.respondWith(fetch("realaudio.ogg"));
     }
+  } else if (event.request.url.indexOf("video.ogg") >= 0) {
+    // FIXME: Bug 1147668: This should be "video".
+    if (event.request.context == "audio") {
+      event.respondWith(fetch("realaudio.ogg"));
+    }
   }
   // Fail any request that we don't know about.
   try {

dom/workers/test/serviceworkers/fetch/context/index.html

@@ -71,12 +71,26 @@
     });
   }
 
+  function testVideo() {
+    return new Promise(function(resolve, reject) {
+      var video = document.createElement("video");
+      video.src = "video.ogg";
+      video.preload = "metadata";
+      // The service worker will respond with an existing video only if the
+      // Request has the correct context, otherwise the Promise will get
+      // rejected and the test will fail.
+      video.onloadedmetadata = resolve;
+      video.onerror = reject;
+    });
+  }
+
   Promise.all([
     testFetch(),
     testImage(),
     testImageSrcSet(),
     testPicture(),
     testAudio(),
+    testVideo(),
   ])
   .then(function() {
     finish();