Bug 1830790 - P2 - webrtc stats history prefs;r=bwc

Depends on D176858

Differential Revision: https://phabricator.services.mozilla.com/D176859

modules/libpref/init/StaticPrefList.yaml

@@ -10832,6 +10832,44 @@
     value: false
     mirror: always
 #endif
+
+  # Interval in milliseconds at which to gather WebRTC stats for use in about:webrtc.
+-   name: media.aboutwebrtc.hist.poll_interval_ms
+    type: RelaxedAtomicUint32
+    value: 250
+    mirror: always
+
+  # History time depth in seconds to keep for webrtc:stats for use in about:webrtc.
+-   name: media.aboutwebrtc.hist.storage_window_s
+    type: RelaxedAtomicUint32
+    value: 60
+    mirror: always
+
+  # Time in minutes to retain peer connection stats after closing.
+-   name: media.aboutwebrtc.hist.prune_after_m
+    type: RelaxedAtomicUint32
+    value: 60 * 24 * 2
+    mirror: always
+
+  # Max number of closed PC stats histories to retain
+-   name: media.aboutwebrtc.hist.closed_stats_to_retain
+    type: RelaxedAtomicUint32
+    value: 8
+    mirror: always
+
+  # Gather PeerConnection stats history for display in about:webrtc. If
+  # disabled history will only gather when about:webrtc is open. Additionally,
+  # if disabled and when about:webrtc is not in the foreground history data
+  # will become sparse.
+-   name: media.aboutwebrtc.hist.enabled
+    type: RelaxedAtomicBool
+#if defined(MOZ_WIDGET_ANDROID)
+    value: false
+#else
+    value: @IS_NIGHTLY_BUILD@
+#endif
+    mirror: always
+
 #endif  # MOZ_WEBRTC
 
 # HTMLMediaElement.allowedToPlay should be exposed to web content when