Bug 1814749 - part3 : add a test. r=jolin

Differential Revision: https://phabricator.services.mozilla.com/D173376

dom/media/test/browser/wmfme/browser.ini

@@ -8,3 +8,4 @@ support-files =
   ../../gizmo.mp4
 
 [browser_wmfme_crash.js]
+[browser_wmfme_max_crashes.js]

dom/media/test/browser/wmfme/browser_wmfme_max_crashes.js

+"use strict";
+
+/**
+ * This test aims to ensure that the MFCDM process won't be recovered once the
+ * amount of crashes has exceeded the amount of value which we tolerate.
+ */
+add_task(async function setupTestingPref() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["media.wmf.media-engine.enabled", true],
+      ["media.wmf.media-engine.channel-decoder.enabled", true],
+    ],
+  });
+});
+
+const VIDEO_PAGE = GetTestWebBasedURL("file_video.html");
+
+add_task(async function testPlaybackRecoveryFromCrash() {
+  const maxCrashes = Services.prefs.getIntPref(
+    "media.wmf.media-engine.max-crashes"
+  );
+  info(`The amount of tolerable crashes=${maxCrashes}`);
+
+  info(`Create a tab and load test page`);
+  let tab = await BrowserTestUtils.openNewForegroundTab(
+    window.gBrowser,
+    "about:blank"
+  );
+  BrowserTestUtils.loadURIString(tab.linkedBrowser, VIDEO_PAGE);
+  await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+
+  await playVideo(tab);
+
+  info("Ensure video is running via the media engine framework");
+  await assertRunningProcessAndDecoderName(tab, {
+    expectedProcess: "Utility MF Media Engine CDM",
+    expectedDecoder: "media engine video stream",
+  });
+
+  let pidBeforeCrash, pidAfterCrash;
+  for (let idx = 0; idx < maxCrashes; idx++) {
+    pidBeforeCrash = await getMFCDMProcessId();
+    await crashUtilityProcess(pidBeforeCrash);
+
+    info("The CDM process should be recreated which makes media keep playing");
+    await assertRunningProcessAndDecoderName(tab, {
+      expectedProcess: "Utility MF Media Engine CDM",
+      expectedDecoder: "media engine video stream",
+    });
+
+    pidAfterCrash = await getMFCDMProcessId();
+    isnot(
+      pidBeforeCrash,
+      pidAfterCrash,
+      `new process ${pidAfterCrash} is not previous crashed one ${pidBeforeCrash}`
+    );
+  }
+
+  info("This crash should result in not spawning MFCDM process again");
+  pidBeforeCrash = await getMFCDMProcessId();
+  await crashUtilityProcess(pidBeforeCrash);
+
+  await assertNotEqualRunningProcessAndDecoderName(tab, {
+    givenProcess: "Utility MF Media Engine CDM",
+    givenDecoder: "media engine video stream",
+  });
+
+  BrowserTestUtils.removeTab(tab);
+});

dom/media/test/browser/wmfme/head.js

@@ -161,3 +161,40 @@ async function assertRunningProcessAndDecoderName(
     }
   );
 }
+
+/**
+ * Check whether the video playback is not performed in the given process and given decoder.
+ * @param {object} tab
+ *        the tab which has a playing video
+ * @param {string} givenProcess
+ *        the process name on which the video playback should not be running
+ * @param {string} givenDecoder
+ *        the decoder name with which the video playback should not be running
+ */
+async function assertNotEqualRunningProcessAndDecoderName(
+  tab,
+  { givenProcess, givenDecoder } = {}
+) {
+  return SpecialPowers.spawn(
+    tab.linkedBrowser,
+    [givenProcess, givenDecoder],
+    // eslint-disable-next-line no-shadow
+    async (givenProcess, givenDecoder) => {
+      const video = content.document.querySelector("video");
+      ok(!video.paused, "checking a playing video");
+
+      const debugInfo = await SpecialPowers.wrap(video).mozRequestDebugInfo();
+      const videoDecoderName = debugInfo.decoder.reader.videoDecoderName;
+      const pattern = /(.+?)\s+\((\S+)\s+remote\)/;
+      const match = videoDecoderName.match(pattern);
+      if (match) {
+        const decoder = match[1];
+        const process = match[2];
+        isnot(decoder, givenDecoder, `Decoder name is not equal`);
+        isnot(process, givenProcess, `Process name is not equal`);
+      } else {
+        ok(false, "failed to match decoder/process name?");
+      }
+    }
+  );
+}