new file mode 100644
--- /dev/null
+++ b/toolkit/actors/PurgeSessionHistoryChild.jsm
@@ -0,0 +1,39 @@
+/* vim: set ts=2 sw=2 sts=2 et tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+var EXPORTED_SYMBOLS = ["PurgeSessionHistoryChild"];
+
+ChromeUtils.import("resource://gre/modules/ActorChild.jsm");
+
+class PurgeSessionHistoryChild extends ActorChild {
+  receiveMessage(message) {
+    if (message.name != "Browser:PurgeSessionHistory") {
+      return;
+    }
+    let sessionHistory = this.docShell.QueryInterface(Ci.nsIWebNavigation).sessionHistory;
+    if (!sessionHistory) {
+      return;
+    }
+
+    // place the entry at current index at the end of the history list, so it won't get removed
+    if (sessionHistory.index < sessionHistory.count - 1) {
+      let legacy = sessionHistory.legacySHistory;
+      legacy.QueryInterface(Ci.nsISHistoryInternal);
+      let indexEntry = legacy.getEntryAtIndex(sessionHistory.index, false);
+      indexEntry.QueryInterface(Ci.nsISHEntry);
+      legacy.addEntry(indexEntry, true);
+    }
+
+    let purge = sessionHistory.count;
+    if (this.content.location.href != "about:blank") {
+      --purge; // Don't remove the page the user's staring at from shistory
+    }
+
+    if (purge > 0) {
+      sessionHistory.legacySHistory.PurgeHistory(purge);
+    }
+  }
+}

--- a/toolkit/actors/moz.build
+++ b/toolkit/actors/moz.build
@@ -6,15 +6,16 @@
 
 FINAL_TARGET_FILES.actors += [
     'AudioPlaybackChild.jsm',
     'DateTimePickerChild.jsm',
     'ExtFindChild.jsm',
     'FindBarChild.jsm',
     'PopupBlockingChild.jsm',
     'PrintingChild.jsm',
+    'PurgeSessionHistoryChild.jsm',
     'SelectChild.jsm',
     'SelectionSourceChild.jsm',
     'ThumbnailsChild.jsm',
     'UnselectedTabHoverChild.jsm',
     'WebChannelChild.jsm',
     'ZoomChild.jsm',
 ]

--- a/toolkit/content/browser-content.js
+++ b/toolkit/content/browser-content.js
@@ -39,40 +39,16 @@ var AutoScrollListener = {
         this._controller = new AutoScrollController(global);
       }
       this._controller.handleEvent(event);
     }
   }
 };
 Services.els.addSystemEventListener(global, "mousedown", AutoScrollListener, true);
 
-addMessageListener("Browser:PurgeSessionHistory", function BrowserPurgeHistory() {
-  let sessionHistory = docShell.QueryInterface(Ci.nsIWebNavigation).sessionHistory;
-  if (!sessionHistory) {
-    return;
-  }
-
-  // place the entry at current index at the end of the history list, so it won't get removed
-  if (sessionHistory.index < sessionHistory.count - 1) {
-    let legacy = sessionHistory.legacySHistory;
-    legacy.QueryInterface(Ci.nsISHistoryInternal);
-    let indexEntry = legacy.getEntryAtIndex(sessionHistory.index, false);
-    indexEntry.QueryInterface(Ci.nsISHEntry);
-    legacy.addEntry(indexEntry, true);
-  }
-
-  let purge = sessionHistory.count;
-  if (global.content.location.href != "about:blank") {
-    --purge; // Don't remove the page the user's staring at from shistory
-  }
-
-  if (purge > 0) {
-    sessionHistory.legacySHistory.PurgeHistory(purge);
-  }
-});
 
 let AutoComplete = {
   _connected: false,
 
   init() {
     addEventListener("unload", this, {once: true});
     addEventListener("DOMContentLoaded", this, {once: true});
     // WebExtension browserAction is preloaded and does not receive DCL, wait

--- a/toolkit/modules/ActorManagerParent.jsm
+++ b/toolkit/modules/ActorManagerParent.jsm
@@ -161,16 +161,25 @@ let ACTORS = {
         "Printing:Preview:Exit",
         "Printing:Preview:Navigate",
         "Printing:Preview:ParseDocument",
         "Printing:Print",
       ],
     },
   },
 
+  PurgeSessionHistory: {
+    child: {
+      module: "resource://gre/actors/PurgeSessionHistoryChild.jsm",
+      messages: [
+        "Browser:PurgeSessionHistory",
+      ],
+    },
+  },
+
   Select: {
     child: {
       module: "resource://gre/actors/SelectChild.jsm",
       events: {
         "mozshowdropdown": {},
         "mozshowdropdown-sourcetouch": {},
       },
     },