Bug 1628779 - Add an entry in about:support for the roundtrip audio latency of default devices r=chunmin,fluent-reviewers,flod

Differential Revision: https://phabricator.services.mozilla.com/D75334

toolkit/content/aboutSupport.js

@@ -919,6 +919,19 @@ var snapshotFormatters = {
     insertBasicInfo("audio-backend", data.currentAudioBackend);
     insertBasicInfo("max-audio-channels", data.currentMaxAudioChannels);
     insertBasicInfo("sample-rate", data.currentPreferredSampleRate);
+    insertBasicInfo("roundtrip-latency", "...");
+    window.windowUtils
+      .defaultDevicesRoundTripLatency()
+      .then(latency => {
+        var latencyString = `${(latency[0] * 1000).toFixed(2)}ms (${(
+          latency[1] * 1000
+        ).toFixed(2)})`;
+        data.defaultDevicesRoundTripLatency = latencyString;
+        document.querySelector(
+          'th[data-l10n-id="roundtrip-latency"]'
+        ).nextSibling.textContent = latencyString;
+      })
+      .catch(e => {});
 
     // Output devices information
     insertDeviceInfo("output", data.audioOutputDevices);

toolkit/locales/en-US/toolkit/about/aboutSupport.ftl

@@ -124,6 +124,7 @@ restart-in-safe-mode-label = Restart with Add-ons Disabled…
 audio-backend = Audio Backend
 max-audio-channels = Max Channels
 sample-rate = Preferred Sample Rate
+roundtrip-latency = Roundtrip latency (standard deviation)
 media-title = Media
 media-output-devices-title = Output Devices
 media-input-devices-title = Input Devices