--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -12612,16 +12612,22 @@ nsIDocument::HasBeenUserGestureActivated
       break;
     }
     doc = doc->GetSameTypeParentDocument();
   }
 
   return mUserGestureActivated;
 }
 
+bool
+nsIDocument::IsExtensionPage() const
+{
+  return BasePrincipal::Cast(NodePrincipal())->AddonPolicy();
+}
+
 nsIDocument*
 nsIDocument::GetSameTypeParentDocument()
 {
   nsCOMPtr<nsIDocShellTreeItem> current = GetDocShell();
   if (!current) {
     return nullptr;
   }
 

--- a/dom/base/nsIDocument.h
+++ b/dom/base/nsIDocument.h
@@ -3434,16 +3434,20 @@ public:
   // permit autoplay audible media. This also gesture activates all other
   // content documents in this tab.
   void NotifyUserGestureActivation();
 
   // Return true if NotifyUserGestureActivation() has been called on any
   // document in the document tree.
   bool HasBeenUserGestureActivated();
 
+  // This document is a WebExtension page, it might be a background page, a
+  // popup, a visible tab, a visible iframe ...e.t.c.
+  bool IsExtensionPage() const;
+
   bool HasScriptsBlockedBySandbox();
 
   bool InlineScriptAllowedByCSP();
 
   void ReportHasScrollLinkedEffect();
   bool HasScrollLinkedEffect() const
   {
     return mHasScrollLinkedEffect;

--- a/dom/media/AutoplayPolicy.cpp
+++ b/dom/media/AutoplayPolicy.cpp
@@ -66,16 +66,21 @@ IsWindowAllowedToPlay(nsPIDOMWindowInner
     return true;
   }
 
   if (approver->HasBeenUserGestureActivated()) {
     // Document has been activated by user gesture.
     return true;
   }
 
+  if (approver->IsExtensionPage()) {
+    // Always allow extension page to autoplay.
+    return true;
+  }
+
   return false;
 }
 
 /* static */
 already_AddRefed<AutoplayPermissionManager>
 AutoplayPolicy::RequestFor(const nsIDocument& aDocument)
 {
   nsIDocument* document = ApproverDocOf(aDocument);