diff --git a/caps/BasePrincipal.cpp b/caps/BasePrincipal.cpp
index 4425e17f9110..c668a19088dc 100644
--- a/caps/BasePrincipal.cpp
+++ b/caps/BasePrincipal.cpp
@@ -24,6 +24,7 @@
 #include "mozilla/dom/BlobURLProtocolHandler.h"
 #include "mozilla/dom/ChromeUtils.h"
 #include "mozilla/dom/ToJSValue.h"
+#include "mozilla/dom/nsMixedContentBlocker.h"
 
 #include "json/json.h"
 #include "nsSerializationHelper.h"
@@ -500,6 +501,21 @@ BasePrincipal::IsURIInPrefList(const char* aPref, bool* aResult) {
   return NS_OK;
 }
 
+NS_IMETHODIMP
+BasePrincipal::GetIsOriginPotentiallyTrustworthy(bool* aResult) {
+  MOZ_ASSERT(NS_IsMainThread());
+  *aResult = false;
+
+  nsCOMPtr<nsIURI> uri;
+  nsresult rv = GetURI(getter_AddRefs(uri));
+  if (NS_FAILED(rv) || !uri) {
+    return NS_OK;
+  }
+
+  *aResult = nsMixedContentBlocker::IsPotentiallyTrustworthyOrigin(uri);
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 BasePrincipal::GetAboutModuleFlags(uint32_t* flags) {
   *flags = 0;
diff --git a/caps/BasePrincipal.h b/caps/BasePrincipal.h
index 68b815257c08..0521500e8f75 100644
--- a/caps/BasePrincipal.h
+++ b/caps/BasePrincipal.h
@@ -133,6 +133,7 @@ class BasePrincipal : public nsJSPrincipals {
   NS_IMETHOD GetSiteOrigin(nsACString& aOrigin) override;
   NS_IMETHOD IsThirdPartyURI(nsIURI* uri, bool* aRes) override;
   NS_IMETHOD IsThirdPartyPrincipal(nsIPrincipal* uri, bool* aRes) override;
+  NS_IMETHOD GetIsOriginPotentiallyTrustworthy(bool* aResult) override;
 
   nsresult ToJSON(nsACString& aJSON);
   static already_AddRefed<BasePrincipal> FromJSON(const nsACString& aJSON);
diff --git a/caps/NullPrincipal.cpp b/caps/NullPrincipal.cpp
index ca29d12e3257..cf3d9468bb26 100644
--- a/caps/NullPrincipal.cpp
+++ b/caps/NullPrincipal.cpp
@@ -136,6 +136,11 @@ NullPrincipal::GetURI(nsIURI** aURI) {
   uri.forget(aURI);
   return NS_OK;
 }
+NS_IMETHODIMP
+NullPrincipal::GetIsOriginPotentiallyTrustworthy(bool* aResult) {
+  *aResult = false;
+  return NS_OK;
+}
 
 NS_IMETHODIMP
 NullPrincipal::GetDomain(nsIURI** aDomain) {
diff --git a/caps/NullPrincipal.h b/caps/NullPrincipal.h
index ec023c5a5c2e..0196716eb7a4 100644
--- a/caps/NullPrincipal.h
+++ b/caps/NullPrincipal.h
@@ -51,6 +51,7 @@ class NullPrincipal final : public BasePrincipal {
   NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override;
   uint32_t GetHashValue() override;
   NS_IMETHOD GetURI(nsIURI** aURI) override;
+  NS_IMETHOD GetIsOriginPotentiallyTrustworthy(bool* aResult) override;
   NS_IMETHOD GetDomain(nsIURI** aDomain) override;
   NS_IMETHOD SetDomain(nsIURI* aDomain) override;
   NS_IMETHOD GetBaseDomain(nsACString& aBaseDomain) override;
diff --git a/caps/SystemPrincipal.cpp b/caps/SystemPrincipal.cpp
index cb9c5aca97ef..b5c3c9337013 100644
--- a/caps/SystemPrincipal.cpp
+++ b/caps/SystemPrincipal.cpp
@@ -51,6 +51,12 @@ SystemPrincipal::GetURI(nsIURI** aURI) {
   return NS_OK;
 }
 
+NS_IMETHODIMP
+SystemPrincipal::GetIsOriginPotentiallyTrustworthy(bool* aResult) {
+  *aResult = true;
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 SystemPrincipal::GetDomain(nsIURI** aDomain) {
   *aDomain = nullptr;
diff --git a/caps/SystemPrincipal.h b/caps/SystemPrincipal.h
index 63bbf692b625..4853632f348b 100644
--- a/caps/SystemPrincipal.h
+++ b/caps/SystemPrincipal.h
@@ -44,6 +44,7 @@ class SystemPrincipal final : public BasePrincipal {
   NS_IMETHOD SetDomain(nsIURI* aDomain) override;
   NS_IMETHOD GetBaseDomain(nsACString& aBaseDomain) override;
   NS_IMETHOD GetAddonId(nsAString& aAddonId) override;
+  NS_IMETHOD GetIsOriginPotentiallyTrustworthy(bool* aResult) override;
 
   virtual nsresult GetScriptLocation(nsACString& aStr) override;
 
diff --git a/caps/nsIPrincipal.idl b/caps/nsIPrincipal.idl
index 2a8d3a34d9a3..3d4ce3859e00 100644
--- a/caps/nsIPrincipal.idl
+++ b/caps/nsIPrincipal.idl
@@ -237,6 +237,18 @@ interface nsIPrincipal : nsISerializable
     */
     bool IsURIInPrefList(in string pref);
 
+    /**
+     * Implementation of
+     * https://w3c.github.io/webappsec-secure-contexts/#is-origin-trustworthy
+     *
+     * The value returned by this method feeds into the the Secure Context
+     * algorithm that determins the value of Window.isSecureContext and
+     * WorkerGlobalScope.isSecureContext.
+     *
+     * This method returns false instead of throwing upon errors.
+     */ 
+    readonly attribute bool IsOriginPotentiallyTrustworthy;
+
     /**
      * Returns the Flags of the Principals 
      * associated AboutModule, in case there is one.
diff --git a/dom/base/nsContentUtils.cpp b/dom/base/nsContentUtils.cpp
index 6db99a516770..b46c9ea7780f 100644
--- a/dom/base/nsContentUtils.cpp
+++ b/dom/base/nsContentUtils.cpp
@@ -8886,18 +8886,9 @@ bool nsContentUtils::HttpsStateIsModern(Document* aDocument) {
 
   MOZ_ASSERT(principal->GetIsContentPrincipal());
 
-  nsCOMPtr<nsIContentSecurityManager> csm =
-      do_GetService(NS_CONTENTSECURITYMANAGER_CONTRACTID);
-  NS_WARNING_ASSERTION(csm, "csm is null");
-  if (csm) {
-    bool isTrustworthyOrigin = false;
-    csm->IsOriginPotentiallyTrustworthy(principal, &isTrustworthyOrigin);
-    if (isTrustworthyOrigin) {
-      return true;
-    }
-  }
-
-  return false;
+  bool isTrustworthyOrigin = false;
+  principal->GetIsOriginPotentiallyTrustworthy(&isTrustworthyOrigin);
+  return isTrustworthyOrigin;
 }
 
 /* static */
@@ -8927,15 +8918,9 @@ bool nsContentUtils::ComputeIsSecureContext(nsIChannel* aChannel) {
     return false;
   }
 
-  nsCOMPtr<nsIContentSecurityManager> csm =
-      do_GetService(NS_CONTENTSECURITYMANAGER_CONTRACTID);
-  NS_WARNING_ASSERTION(csm, "csm is null");
-  if (csm) {
-    bool isTrustworthyOrigin = false;
-    csm->IsOriginPotentiallyTrustworthy(principal, &isTrustworthyOrigin);
-    return isTrustworthyOrigin;
-  }
-  return true;
+  bool isTrustworthyOrigin = false;
+  principal->GetIsOriginPotentiallyTrustworthy(&isTrustworthyOrigin);
+  return isTrustworthyOrigin;
 }
 
 /* static */
diff --git a/dom/base/nsGlobalWindowOuter.cpp b/dom/base/nsGlobalWindowOuter.cpp
index 6b07e6d409b3..c6d96ac91072 100644
--- a/dom/base/nsGlobalWindowOuter.cpp
+++ b/dom/base/nsGlobalWindowOuter.cpp
@@ -1699,18 +1699,9 @@ bool nsGlobalWindowOuter::ComputeIsSecureContext(Document* aDocument,
     }
   }
 
-  nsCOMPtr<nsIContentSecurityManager> csm =
-      do_GetService(NS_CONTENTSECURITYMANAGER_CONTRACTID);
-  NS_WARNING_ASSERTION(csm, "csm is null");
-  if (csm) {
-    bool isTrustworthyOrigin = false;
-    csm->IsOriginPotentiallyTrustworthy(principal, &isTrustworthyOrigin);
-    if (isTrustworthyOrigin) {
-      return true;
-    }
-  }
-
-  return false;
+  bool isTrustworthyOrigin = false;
+  principal->GetIsOriginPotentiallyTrustworthy(&isTrustworthyOrigin);
+  return isTrustworthyOrigin;
 }
 
 // We need certain special behavior for remote XUL whitelisted domains, but we
diff --git a/dom/interfaces/security/nsIContentSecurityManager.idl b/dom/interfaces/security/nsIContentSecurityManager.idl
index 1a1c91021751..5cd2feffad19 100644
--- a/dom/interfaces/security/nsIContentSecurityManager.idl
+++ b/dom/interfaces/security/nsIContentSecurityManager.idl
@@ -42,15 +42,4 @@ interface nsIContentSecurityManager : nsISupports
    nsIStreamListener performSecurityCheck(in nsIChannel aChannel,
                                           in nsIStreamListener aStreamListener);
 
-  /**
-   * Implementation of
-   * https://w3c.github.io/webappsec-secure-contexts/#is-origin-trustworthy
-   *
-   * The value returned by this method feeds into the the Secure Context
-   * algorithm that determins the value of Window.isSecureContext and
-   * WorkerGlobalScope.isSecureContext.
-   *
-   * This method returns false instead of throwing upon errors.
-   */
-  boolean isOriginPotentiallyTrustworthy(in nsIPrincipal aPrincipal);
 };
diff --git a/dom/presentation/PresentationRequest.cpp b/dom/presentation/PresentationRequest.cpp
index fd2f1fc08851..fd0c887429dd 100644
--- a/dom/presentation/PresentationRequest.cpp
+++ b/dom/presentation/PresentationRequest.cpp
@@ -509,14 +509,8 @@ bool PresentationRequest::IsPrioriAuthenticatedURL(const nsAString& aUrl) {
     return false;
   }
 
-  nsCOMPtr<nsIContentSecurityManager> csm =
-      do_GetService(NS_CONTENTSECURITYMANAGER_CONTRACTID);
-  if (NS_WARN_IF(!csm)) {
-    return false;
-  }
-
   bool isTrustworthyOrigin = false;
-  csm->IsOriginPotentiallyTrustworthy(principal, &isTrustworthyOrigin);
+  principal->GetIsOriginPotentiallyTrustworthy(&isTrustworthyOrigin);
   return isTrustworthyOrigin;
 }
 
diff --git a/dom/security/nsContentSecurityManager.cpp b/dom/security/nsContentSecurityManager.cpp
index 7dcc6332477e..0ad318054139 100644
--- a/dom/security/nsContentSecurityManager.cpp
+++ b/dom/security/nsContentSecurityManager.cpp
@@ -1059,30 +1059,3 @@ nsContentSecurityManager::PerformSecurityCheck(
   inAndOutListener.forget(outStreamListener);
   return NS_OK;
 }
-
-NS_IMETHODIMP
-nsContentSecurityManager::IsOriginPotentiallyTrustworthy(
-    nsIPrincipal* aPrincipal, bool* aIsTrustWorthy) {
-  MOZ_ASSERT(NS_IsMainThread());
-  NS_ENSURE_ARG_POINTER(aPrincipal);
-  NS_ENSURE_ARG_POINTER(aIsTrustWorthy);
-
-  if (aPrincipal->IsSystemPrincipal()) {
-    *aIsTrustWorthy = true;
-    return NS_OK;
-  }
-  *aIsTrustWorthy = false;
-  if (aPrincipal->GetIsNullPrincipal()) {
-    return NS_OK;
-  }
-
-  MOZ_ASSERT(aPrincipal->GetIsContentPrincipal(),
-             "Nobody is expected to call us with an nsIExpandedPrincipal");
-
-  nsCOMPtr<nsIURI> uri;
-  nsresult rv = aPrincipal->GetURI(getter_AddRefs(uri));
-  NS_ENSURE_SUCCESS(rv, rv);
-  *aIsTrustWorthy = nsMixedContentBlocker::IsPotentiallyTrustworthyOrigin(uri);
-
-  return NS_OK;
-}
diff --git a/dom/security/test/gtest/TestSecureContext.cpp b/dom/security/test/gtest/TestSecureContext.cpp
index fa6678dc9396..f971963d9e7d 100644
--- a/dom/security/test/gtest/TestSecureContext.cpp
+++ b/dom/security/test/gtest/TestSecureContext.cpp
@@ -70,8 +70,7 @@ TEST(SecureContext, IsOriginPotentiallyTrustworthyWithContentPrincipal)
     rv = nsScriptSecurityManager::GetScriptSecurityManager()
              ->CreateContentPrincipalFromOrigin(uri, getter_AddRefs(prin));
     bool isPotentiallyTrustworthy = false;
-    rv = csManager->IsOriginPotentiallyTrustworthy(prin,
-                                                   &isPotentiallyTrustworthy);
+    rv = prin->GetIsOriginPotentiallyTrustworthy(&isPotentiallyTrustworthy);
     ASSERT_EQ(NS_OK, rv);
     ASSERT_EQ(isPotentiallyTrustworthy, uris[i].expectedResult);
   }
@@ -82,14 +81,10 @@ TEST(SecureContext, IsOriginPotentiallyTrustworthyWithSystemPrincipal)
   RefPtr<nsScriptSecurityManager> ssManager =
       nsScriptSecurityManager::GetScriptSecurityManager();
   ASSERT_TRUE(!!ssManager);
-  nsCOMPtr<nsIContentSecurityManager> csManager =
-      do_GetService(NS_CONTENTSECURITYMANAGER_CONTRACTID);
-  ASSERT_TRUE(!!csManager);
-
   nsCOMPtr<nsIPrincipal> sysPrin = nsContentUtils::GetSystemPrincipal();
   bool isPotentiallyTrustworthy;
-  nsresult rv = csManager->IsOriginPotentiallyTrustworthy(
-      sysPrin, &isPotentiallyTrustworthy);
+  nsresult rv =
+      sysPrin->GetIsOriginPotentiallyTrustworthy(&isPotentiallyTrustworthy);
   ASSERT_EQ(rv, NS_OK);
   ASSERT_TRUE(isPotentiallyTrustworthy);
 }
@@ -99,15 +94,12 @@ TEST(SecureContext, IsOriginPotentiallyTrustworthyWithNullPrincipal)
   RefPtr<nsScriptSecurityManager> ssManager =
       nsScriptSecurityManager::GetScriptSecurityManager();
   ASSERT_TRUE(!!ssManager);
-  nsCOMPtr<nsIContentSecurityManager> csManager =
-      do_GetService(NS_CONTENTSECURITYMANAGER_CONTRACTID);
-  ASSERT_TRUE(!!csManager);
 
   RefPtr<NullPrincipal> nullPrin =
       NullPrincipal::CreateWithoutOriginAttributes();
   bool isPotentiallyTrustworthy;
-  nsresult rv = csManager->IsOriginPotentiallyTrustworthy(
-      nullPrin, &isPotentiallyTrustworthy);
+  nsresult rv =
+      nullPrin->GetIsOriginPotentiallyTrustworthy(&isPotentiallyTrustworthy);
   ASSERT_EQ(rv, NS_OK);
   ASSERT_TRUE(!isPotentiallyTrustworthy);
 }
diff --git a/dom/security/test/unit/test_isOriginPotentiallyTrustworthy.js b/dom/security/test/unit/test_isOriginPotentiallyTrustworthy.js
index e5bc3f7dcb87..b88c6ed83048 100644
--- a/dom/security/test/unit/test_isOriginPotentiallyTrustworthy.js
+++ b/dom/security/test/unit/test_isOriginPotentiallyTrustworthy.js
@@ -49,18 +49,12 @@ add_task(async function test_isOriginPotentiallyTrustworthy() {
   ]) {
     let uri = NetUtil.newURI(uriSpec);
     let principal = gScriptSecurityManager.createContentPrincipal(uri, {});
-    Assert.equal(
-      gContentSecurityManager.isOriginPotentiallyTrustworthy(principal),
-      expectedResult
-    );
+    Assert.equal(principal.IsOriginPotentiallyTrustworthy, expectedResult);
   }
   // And now let's test whether .onion sites are properly treated when
   // whitelisted, see bug 1382359.
   Services.prefs.setBoolPref("dom.securecontext.whitelist_onions", true);
   let uri = NetUtil.newURI("http://1234567890abcdef.onion/");
   let principal = gScriptSecurityManager.createContentPrincipal(uri, {});
-  Assert.equal(
-    gContentSecurityManager.isOriginPotentiallyTrustworthy(principal),
-    true
-  );
+  Assert.equal(principal.IsOriginPotentiallyTrustworthy, true);
 });
diff --git a/toolkit/components/clearsitedata/ClearSiteData.cpp b/toolkit/components/clearsitedata/ClearSiteData.cpp
index e056648b7468..e2760fc83265 100644
--- a/toolkit/components/clearsitedata/ClearSiteData.cpp
+++ b/toolkit/components/clearsitedata/ClearSiteData.cpp
@@ -162,11 +162,8 @@ void ClearSiteData::ClearDataFromChannel(nsIHttpChannel* aChannel) {
     return;
   }
 
-  nsCOMPtr<nsIContentSecurityManager> csm =
-      do_GetService(NS_CONTENTSECURITYMANAGER_CONTRACTID);
-
   bool secure;
-  rv = csm->IsOriginPotentiallyTrustworthy(principal, &secure);
+  rv = principal->GetIsOriginPotentiallyTrustworthy(&secure);
   if (NS_WARN_IF(NS_FAILED(rv)) || !secure) {
     return;
   }
diff --git a/toolkit/components/extensions/test/xpcshell/test_ext_trustworthy_origin.js b/toolkit/components/extensions/test/xpcshell/test_ext_trustworthy_origin.js
index 0c6dd0b6f393..18a92a350969 100644
--- a/toolkit/components/extensions/test/xpcshell/test_ext_trustworthy_origin.js
+++ b/toolkit/components/extensions/test/xpcshell/test_ext_trustworthy_origin.js
@@ -6,16 +6,13 @@
 
 add_task(
   function test_isOriginPotentiallyTrustworthnsIContentSecurityManagery() {
-    let contentSecManager = Cc[
-      "@mozilla.org/contentsecuritymanager;1"
-    ].getService(Ci.nsIContentSecurityManager);
     let uri = NetUtil.newURI("moz-extension://foobar/something.html");
     let principal = Services.scriptSecurityManager.createContentPrincipal(
       uri,
       {}
     );
     Assert.equal(
-      contentSecManager.isOriginPotentiallyTrustworthy(principal),
+      principal.IsOriginPotentiallyTrustworthy,
       true,
       "it is potentially trustworthy"
     );
diff --git a/toolkit/components/passwordmgr/InsecurePasswordUtils.jsm b/toolkit/components/passwordmgr/InsecurePasswordUtils.jsm
index 67ae38b85489..9d241728814c 100644
--- a/toolkit/components/passwordmgr/InsecurePasswordUtils.jsm
+++ b/toolkit/components/passwordmgr/InsecurePasswordUtils.jsm
@@ -100,7 +100,7 @@ this.InsecurePasswordUtils = {
       if (uri.schemeIs("http")) {
         isFormSubmitHTTP = true;
         if (
-          gContentSecurityManager.isOriginPotentiallyTrustworthy(principal) ||
+          principal.IsOriginPotentiallyTrustworthy ||
           // Ignore sites with local IP addresses pointing to local forms.
           (this._isPrincipalForLocalIPAddress(
             aForm.rootElement.nodePrincipal