foo.diff

diff --git a/browser/app/profile/firefox.js b/browser/app/profile/firefox.js
index 2c1a547dce87..9e0f0b38a36c 100644
--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -221,7 +221,7 @@ pref("browser.defaultbrowser.notificationbar", false);
 // 0 = blank, 1 = home (browser.startup.homepage), 2 = last visited page, 3 = resume previous browser session
 // The behavior of option 3 is detailed at: http://wiki.mozilla.org/Session_Restore
 pref("browser.startup.page",                1);
-pref("browser.startup.homepage",            "http://google.com");
+pref("browser.startup.homepage",            "http://localhost:3000");
 pref("browser.startup.homepage.abouthome_cache.enabled", false);
 
 // Whether we should skip the homepage when opening the first-run page
diff --git a/devtools/startup/DevToolsStartup.jsm b/devtools/startup/DevToolsStartup.jsm
index 01fceea4165e..8eba45c697ca 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 +699,40 @@ DevToolsStartup.prototype = {
     }
   },
 
+  initializeRecordingWebChannel() {
+    let channel;
+    console.log(`>> initializeRecordingWebChannel`);
+
+    // 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/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 62fbce38f258..bbdf854de6c2 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -843,6 +843,7 @@ pref("devtools.recordreplay.cloudServer", "wss://dispatch.replay.io");
 
 // Whether to upload source maps and original sources to the cloud server.
 pref("devtools.recordreplay.uploadSourceMaps", true);
+pref("devtools.recordreplay.ui-base-url", "http://localhost:3000")
 
 // Preferences for the new performance panel.
 // This pref configures the base URL for the profiler.firefox.com instance 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,