--- a/caps/nsScriptSecurityManager.cpp
+++ b/caps/nsScriptSecurityManager.cpp
@@ -340,30 +340,16 @@ nsScriptSecurityManager::GetChannelResul
                 principalToInherit.forget(aPrincipal);
                 return NS_OK;
             }
         }
     }
     return GetChannelURIPrincipal(aChannel, aPrincipal);
 }
 
-nsresult
-nsScriptSecurityManager::MaybeSetAddonIdFromURI(OriginAttributes& aAttrs, nsIURI* aURI)
-{
-  nsAutoCString scheme;
-  nsresult rv = aURI->GetScheme(scheme);
-  NS_ENSURE_SUCCESS(rv, rv);
-  if (scheme.EqualsLiteral("moz-extension") && GetAddonPolicyService()) {
-    rv = GetAddonPolicyService()->ExtensionURIToAddonId(aURI, aAttrs.mAddonId);
-    NS_ENSURE_SUCCESS(rv, rv);
-  }
-
-  return NS_OK;
-}
-
 /* The principal of the URI that this channel is loading. This is never
  * affected by things like sandboxed loads, or loads where we forcefully
  * inherit the principal.  Think of this as the principal of the server
  * which this channel is loading from.  Most callers should use
  * GetChannelResultPrincipal instead of GetChannelURIPrincipal.  Only
  * call GetChannelURIPrincipal if you are sure that you want the
  * principal that matches the uri, even in cases when the load is
  * sandboxed or when the load could be a blob or data uri (i.e even when
@@ -391,18 +377,16 @@ nsScriptSecurityManager::GetChannelURIPr
     // For subresource loading, the origin attributes of the loadInfo is from
     // its loadingPrincipal.
     OriginAttributes attrs;
 
     // For addons loadInfo might be null.
     if (loadInfo) {
       attrs.Inherit(loadInfo->GetOriginAttributes());
     }
-    rv = MaybeSetAddonIdFromURI(attrs, uri);
-    NS_ENSURE_SUCCESS(rv, rv);
     nsCOMPtr<nsIPrincipal> prin = BasePrincipal::CreateCodebasePrincipal(uri, attrs);
     prin.forget(aPrincipal);
     return *aPrincipal ? NS_OK : NS_ERROR_FAILURE;
 }
 
 NS_IMETHODIMP
 nsScriptSecurityManager::IsSystemPrincipal(nsIPrincipal* aPrincipal,
                                            bool* aIsSystem)
@@ -1161,33 +1145,29 @@ nsScriptSecurityManager::
   NS_ENSURE_STATE(aLoadContext);
   OriginAttributes docShellAttrs;
   bool result = aLoadContext->GetOriginAttributes(docShellAttrs);;
   NS_ENSURE_TRUE(result, NS_ERROR_FAILURE);
 
   OriginAttributes attrs;
   attrs.Inherit(docShellAttrs);
 
-  nsresult rv = MaybeSetAddonIdFromURI(attrs, aURI);
-  NS_ENSURE_SUCCESS(rv, rv);
   nsCOMPtr<nsIPrincipal> prin = BasePrincipal::CreateCodebasePrincipal(aURI, attrs);
   prin.forget(aPrincipal);
   return *aPrincipal ? NS_OK : NS_ERROR_FAILURE;
 }
 
 NS_IMETHODIMP
 nsScriptSecurityManager::GetDocShellCodebasePrincipal(nsIURI* aURI,
                                                       nsIDocShell* aDocShell,
                                                       nsIPrincipal** aPrincipal)
 {
   OriginAttributes attrs;
   attrs.Inherit(nsDocShell::Cast(aDocShell)->GetOriginAttributes());
 
-  nsresult rv = MaybeSetAddonIdFromURI(attrs, aURI);
-  NS_ENSURE_SUCCESS(rv, rv);
   nsCOMPtr<nsIPrincipal> prin = BasePrincipal::CreateCodebasePrincipal(aURI, attrs);
   prin.forget(aPrincipal);
   return *aPrincipal ? NS_OK : NS_ERROR_FAILURE;
 }
 
 // static
 nsIPrincipal*
 nsScriptSecurityManager::doGetObjectPrincipal(JSObject *aObj)

--- a/caps/nsScriptSecurityManager.h
+++ b/caps/nsScriptSecurityManager.h
@@ -106,19 +106,16 @@ private:
     InitPrefs();
 
     inline void
     ScriptSecurityPrefChanged();
 
     inline void
     AddSitesToFileURIWhitelist(const nsCString& aSiteList);
 
-    // If aURI is a moz-extension:// URI, set mAddonId to the associated addon.
-    nsresult MaybeSetAddonIdFromURI(mozilla::OriginAttributes& aAttrs, nsIURI* aURI);
-
     nsresult GetChannelResultPrincipal(nsIChannel* aChannel,
                                        nsIPrincipal** aPrincipal,
                                        bool aIgnoreSandboxing);
 
     nsresult
     CheckLoadURIFlags(nsIURI* aSourceURI, nsIURI* aTargetURI, nsIURI* aSourceBaseURI,
                       nsIURI* aTargetBaseURI, uint32_t aFlags);
 

--- a/docshell/base/nsDocShell.cpp
+++ b/docshell/base/nsDocShell.cpp
@@ -9,17 +9,16 @@
 #include <algorithm>
 
 #include "mozilla/ArrayUtils.h"
 #include "mozilla/Attributes.h"
 #include "mozilla/AutoRestore.h"
 #include "mozilla/BasePrincipal.h"
 #include "mozilla/Casting.h"
 #include "mozilla/dom/ContentChild.h"
-#include "mozilla/dom/ChromeUtils.h"
 #include "mozilla/dom/Element.h"
 #include "mozilla/dom/PendingGlobalHistoryEntry.h"
 #include "mozilla/dom/TabChild.h"
 #include "mozilla/dom/ProfileTimelineMarkerBinding.h"
 #include "mozilla/dom/ScreenOrientation.h"
 #include "mozilla/dom/ToJSValue.h"
 #include "mozilla/dom/PermissionMessageUtils.h"
 #include "mozilla/dom/workers/ServiceWorkerManager.h"
@@ -8034,19 +8033,17 @@ nsDocShell::CreateAboutBlankContentViewe
   // mContentViewer->PermitUnload may release |this| docshell.
   nsCOMPtr<nsIDocShell> kungFuDeathGrip(this);
 
   AutoRestore<bool> creatingDocument(mCreatingDocument);
   mCreatingDocument = true;
 
   if (aPrincipal && !nsContentUtils::IsSystemPrincipal(aPrincipal) &&
       mItemType != typeChrome) {
-    MOZ_ASSERT(ChromeUtils::IsOriginAttributesEqualIgnoringAddonId(
-      aPrincipal->OriginAttributesRef(),
-      mOriginAttributes));
+    MOZ_ASSERT(aPrincipal->OriginAttributesRef() == mOriginAttributes);
   }
 
   // Make sure timing is created.  But first record whether we had it
   // already, so we don't clobber the timing for an in-progress load.
   bool hadTiming = mTiming;
   bool toBeReset = MaybeInitTiming();
   if (mContentViewer) {
     if (aCheckPermitUnload) {

--- a/dom/base/PostMessageEvent.cpp
+++ b/dom/base/PostMessageEvent.cpp
@@ -100,17 +100,17 @@ PostMessageEvent::Run()
     if (NS_WARN_IF(!targetPrin))
       return NS_OK;
 
     // Note: This is contrary to the spec with respect to file: URLs, which
     //       the spec groups into a single origin, but given we intentionally
     //       don't do that in other places it seems better to hold the line for
     //       now.  Long-term, we want HTML5 to address this so that we can
     //       be compliant while being safer.
-    if (!BasePrincipal::Cast(targetPrin)->EqualsIgnoringAddonId(mProvidedPrincipal)) {
+    if (!targetPrin->Equals(mProvidedPrincipal)) {
       nsAutoString providedOrigin, targetOrigin;
       nsresult rv = nsContentUtils::GetUTFOrigin(targetPrin, targetOrigin);
       NS_ENSURE_SUCCESS(rv, rv);
       rv = nsContentUtils::GetUTFOrigin(mProvidedPrincipal, providedOrigin);
       NS_ENSURE_SUCCESS(rv, rv);
 
       MOZ_DIAGNOSTIC_ASSERT(providedOrigin != targetOrigin ||
                             (mProvidedPrincipal->OriginAttributesRef() ==

--- a/toolkit/components/extensions/Extension.jsm
+++ b/toolkit/components/extensions/Extension.jsm
@@ -189,23 +189,21 @@ var UninstallObserver = {
 
     if (!this.leaveStorage) {
       // Clear browser.local.storage
       ExtensionStorage.clear(addon.id);
 
       // Clear any IndexedDB storage created by the extension
       let baseURI = NetUtil.newURI(`moz-extension://${uuid}/`);
       let principal = Services.scriptSecurityManager.createCodebasePrincipal(
-        baseURI, {addonId: addon.id}
-      );
+        baseURI, {});
       Services.qms.clearStoragesForPrincipal(principal);
 
       // Clear localStorage created by the extension
-      let attrs = JSON.stringify({addonId: addon.id});
-      Services.obs.notifyObservers(null, "clear-origin-attributes-data", attrs);
+      Services.domStorageManager.getStorage(null, principal).clear();
     }
 
     if (!this.leaveUuid) {
       // Clear the entry in the UUID map
       UUIDMap.remove(addon.id);
     }
   },
 };
@@ -707,18 +705,17 @@ this.Extension = class extends Extension
     }
   }
 
   testMessage(...args) {
     this.emit("test-harness-message", ...args);
   }
 
   createPrincipal(uri = this.baseURI) {
-    return Services.scriptSecurityManager.createCodebasePrincipal(
-      uri, {addonId: this.id});
+    return Services.scriptSecurityManager.createCodebasePrincipal(uri, {});
   }
 
   // Checks that the given URL is a child of our baseURI.
   isExtensionURL(url) {
     let uri = Services.io.newURI(url);
 
     let common = this.baseURI.getCommonBaseSpec(uri);
     return common == this.baseURI.spec;

--- a/toolkit/components/extensions/ExtensionContent.jsm
+++ b/toolkit/components/extensions/ExtensionContent.jsm
@@ -326,20 +326,19 @@ class ContentScriptContextChild extends 
     let frameId = WebNavigationFrames.getFrameId(contentWindow);
     this.frameId = frameId;
 
     this.scripts = [];
 
     let contentPrincipal = contentWindow.document.nodePrincipal;
     let ssm = Services.scriptSecurityManager;
 
-    // copy origin attributes from the content window origin attributes to
-    // preserve the user context id. overwrite the addonId.
+    // Copy origin attributes from the content window origin attributes to
+    // preserve the user context id.
     let attrs = contentPrincipal.originAttributes;
-    attrs.addonId = this.extension.id;
     let extensionPrincipal = ssm.createCodebasePrincipal(this.extension.baseURI, attrs);
 
     let principal;
     if (ssm.isSystemPrincipal(contentPrincipal)) {
       // Make sure we don't hand out the system principal by accident.
       // also make sure that the null principal has the right origin attributes
       principal = ssm.createNullPrincipal(attrs);
     } else {