foo.diff

diff --git a/devtools/startup/DevToolsStartup.jsm b/devtools/startup/DevToolsStartup.jsm
index 01fceea4165e..1b727d124fc8 100644
--- a/devtools/startup/DevToolsStartup.jsm
+++ b/devtools/startup/DevToolsStartup.jsm
@@ -620,6 +620,7 @@ DevToolsStartup.prototype = {
       return;
     }
     this.recordingButtonCreated = true;
+    this.initializeRecordingWebChannel();
 
     createRecordingButton();
   },
@@ -698,6 +699,39 @@ DevToolsStartup.prototype = {
     }
   },
 
+  initializeRecordingWebChannel() {
+    let channel;
+
+    // Register a channel for the URL in preferences. Also update the WebChannel if
+    // the URL changes.
+    const urlPref = "devtools.recordreplay.ui-base-url";
+    Services.prefs.addObserver(urlPref, registerWebChannel);
+    registerWebChannel();
+
+    function registerWebChannel() {
+      console.log(
+        `>> register recording`,
+        Services.prefs.getStringPref(urlPref)
+      );
+
+      if (channel) {
+        channel.stopListening();
+      }
+
+      const urlForWebChannel = Services.io.newURI(
+        Services.prefs.getStringPref(urlPref)
+      );
+
+      channel = new WebChannel("record-replay", urlForWebChannel);
+
+      channel.listen((id, message, target) => {
+        // Defer loading the ProfilerPopupBackground script until it's absolutely needed,
+        // as this code path gets loaded at startup.
+        console.log(`>>>> blowza`, { id, message });
+        dump(`>>> blowze ${id} ${JSON.stringify(message)}\n\n`);
+      });
+    }
+  },
   /*
    * We listen to the "Web Developer" system menu, which is under "Tools" main item.
    * This menu item is hardcoded empty in Firefox UI. We listen for its opening to
diff --git a/toolkit/actors/WebChannelParent.jsm b/toolkit/actors/WebChannelParent.jsm
index 7fdeeaf4909e..e2815b63871d 100644
--- a/toolkit/actors/WebChannelParent.jsm
+++ b/toolkit/actors/WebChannelParent.jsm
@@ -14,6 +14,7 @@ const ERRNO_NO_SUCH_CHANNEL = 2;
 
 class WebChannelParent extends JSWindowActorParent {
   receiveMessage(msg) {
+    dump(`>>> WebChannelParent::receiveMessage \n`);
     let data = msg.data.contentData;
     let sendingContext = {
       browsingContext: this.browsingContext,