diff --git a/caps/BasePrincipal.cpp b/caps/BasePrincipal.cpp
index 2926493d510c..44fcbc245cc2 100644
--- a/caps/BasePrincipal.cpp
+++ b/caps/BasePrincipal.cpp
@@ -351,6 +351,19 @@ OriginAttributes::IsFirstPartyEnabled()
   return sFirstPartyIsolation;
 }
 
+/* static */
+bool
+OriginAttributes::IsPrivateBrowsing(const nsACString& aOrigin)
+{
+  nsAutoCString dummy;
+  PrincipalOriginAttributes attrs;
+  if (NS_WARN_IF(!attrs.PopulateFromOrigin(aOrigin, dummy))) {
+    return false;
+  }
+
+  return !!attrs.mPrivateBrowsingId;
+}
+
 BasePrincipal::BasePrincipal()
 {}
 
diff --git a/caps/BasePrincipal.h b/caps/BasePrincipal.h
index 4c9ad9c3a452..bf1e27aa91b4 100644
--- a/caps/BasePrincipal.h
+++ b/caps/BasePrincipal.h
@@ -68,6 +68,10 @@ public:
   // check if "privacy.firstparty.isolate" is enabled.
   static bool IsFirstPartyEnabled();
 
+  // returns true if the originAttributes suffix has mPrivateBrowsingId value
+  // different than 0.
+  static bool IsPrivateBrowsing(const nsACString& aOrigin);
+
 protected:
   OriginAttributes() {}
   explicit OriginAttributes(const OriginAttributesDictionary& aOther)
diff --git a/dom/media/MediaManager.cpp b/dom/media/MediaManager.cpp
index ead1258826e3..1f0bdb2b05d3 100644
--- a/dom/media/MediaManager.cpp
+++ b/dom/media/MediaManager.cpp
@@ -1230,10 +1230,10 @@ public:
     // We won't need mOnFailure now.
     mOnFailure = nullptr;
 
-    if (!MediaManager::IsPrivateBrowsing(window)) {
+    if (!OriginAttributes::IsPrivateBrowsing(mOrigin)) {
       // Call GetOriginKey again, this time w/persist = true, to promote
       // deviceIds to persistent, in case they're not already. Fire'n'forget.
-      RefPtr<Pledge<nsCString>> p = media::GetOriginKey(mOrigin, false, true);
+      RefPtr<Pledge<nsCString>> p = media::GetOriginKey(mOrigin, true);
     }
     return NS_OK;
   }
@@ -1934,13 +1934,6 @@ MediaManager::NotifyRecordingStatusChange(nsPIDOMWindowInner* aWindow,
   return NS_OK;
 }
 
-bool MediaManager::IsPrivateBrowsing(nsPIDOMWindowInner* window)
-{
-  nsCOMPtr<nsIDocument> doc = window->GetDoc();
-  nsCOMPtr<nsILoadContext> loadContext = doc->GetLoadContext();
-  return loadContext && loadContext->UsePrivateBrowsing();
-}
-
 int MediaManager::AddDeviceChangeCallback(DeviceChangeCallback* aCallback)
 {
   bool fakeDeviceChangeEventOn = mPrefs.mFakeDeviceChangeEventOn;
@@ -2497,7 +2490,6 @@ MediaManager::EnumerateDevicesImpl(uint64_t aWindowId,
   // 2. Get the raw devices list
   // 3. Anonymize the raw list with the origin-key.
 
-  bool privateBrowsing = IsPrivateBrowsing(window);
   nsCOMPtr<nsIPrincipal> principal =
     nsGlobalWindow::Cast(window)->GetPrincipal();
   MOZ_ASSERT(principal);
@@ -2512,8 +2504,7 @@ MediaManager::EnumerateDevicesImpl(uint64_t aWindowId,
   // thread later once GetOriginKey resolves. Needed variables are "captured"
   // (passed by value) safely into the lambda.
 
-  RefPtr<Pledge<nsCString>> p = media::GetOriginKey(origin, privateBrowsing,
-                                                      persist);
+  RefPtr<Pledge<nsCString>> p = media::GetOriginKey(origin, persist);
   p->Then([id, aWindowId, aVideoType, aAudioType,
            aFake](const nsCString& aOriginKey) mutable {
     MOZ_ASSERT(NS_IsMainThread());
diff --git a/dom/media/MediaManager.h b/dom/media/MediaManager.h
index 1255f6c90b41..cf6b93698e69 100644
--- a/dom/media/MediaManager.h
+++ b/dom/media/MediaManager.h
@@ -257,7 +257,6 @@ public:
   MediaEnginePrefs mPrefs;
 
   typedef nsTArray<RefPtr<MediaDevice>> SourceSet;
-  static bool IsPrivateBrowsing(nsPIDOMWindowInner* window);
 
   virtual int AddDeviceChangeCallback(DeviceChangeCallback* aCallback) override;
   virtual void OnDeviceChange() override;
diff --git a/dom/media/eme/CDMProxy.h b/dom/media/eme/CDMProxy.h
index f3f1add43f57..c927b28a0655 100644
--- a/dom/media/eme/CDMProxy.h
+++ b/dom/media/eme/CDMProxy.h
@@ -95,8 +95,7 @@ public:
   virtual void Init(PromiseId aPromiseId,
                     const nsAString& aOrigin,
                     const nsAString& aTopLevelOrigin,
-                    const nsAString& aName,
-                    bool aInPrivateBrowsing) = 0;
+                    const nsAString& aName) = 0;
 
   virtual void OnSetDecryptorId(uint32_t aId) {}
 
diff --git a/dom/media/eme/MediaKeys.cpp b/dom/media/eme/MediaKeys.cpp
index 0b3dba68dc62..a703a8fe6698 100644
--- a/dom/media/eme/MediaKeys.cpp
+++ b/dom/media/eme/MediaKeys.cpp
@@ -409,14 +409,10 @@ MediaKeys::Init(ErrorResult& aRv)
     return promise.forget();
   }
 
-  nsIDocument* doc = window->GetExtantDoc();
-  const bool inPrivateBrowsing = nsContentUtils::IsInPrivateBrowsing(doc);
-
-  EME_LOG("MediaKeys[%p]::Create() (%s, %s), %s",
+  EME_LOG("MediaKeys[%p]::Create() (%s, %s)",
           this,
           origin.get(),
-          topLevelOrigin.get(),
-          (inPrivateBrowsing ? "PrivateBrowsing" : "NonPrivateBrowsing"));
+          topLevelOrigin.get());
 
   // The CDMProxy's initialization is asynchronous. The MediaKeys is
   // refcounted, and its instance is returned to JS by promise once
@@ -432,8 +428,7 @@ MediaKeys::Init(ErrorResult& aRv)
   mProxy->Init(mCreatePromiseId,
                NS_ConvertUTF8toUTF16(origin),
                NS_ConvertUTF8toUTF16(topLevelOrigin),
-               KeySystemToGMPName(mKeySystem),
-               inPrivateBrowsing);
+               KeySystemToGMPName(mKeySystem));
 
   return promise.forget();
 }
diff --git a/dom/media/eme/mediadrm/MediaDrmCDMProxy.cpp b/dom/media/eme/mediadrm/MediaDrmCDMProxy.cpp
index 8c83defcb2b5..5266990a3496 100644
--- a/dom/media/eme/mediadrm/MediaDrmCDMProxy.cpp
+++ b/dom/media/eme/mediadrm/MediaDrmCDMProxy.cpp
@@ -46,16 +46,14 @@ void
 MediaDrmCDMProxy::Init(PromiseId aPromiseId,
                        const nsAString& aOrigin,
                        const nsAString& aTopLevelOrigin,
-                       const nsAString& aName,
-                       bool aInPrivateBrowsing)
+                       const nsAString& aName)
 {
   MOZ_ASSERT(NS_IsMainThread());
   NS_ENSURE_TRUE_VOID(!mKeys.IsNull());
 
   EME_LOG("MediaDrmCDMProxy::Init (%s, %s) %s",
           NS_ConvertUTF16toUTF8(aOrigin).get(),
-          NS_ConvertUTF16toUTF8(aTopLevelOrigin).get(),
-          (aInPrivateBrowsing ? "PrivateBrowsing" : "NonPrivateBrowsing"));
+          NS_ConvertUTF16toUTF8(aTopLevelOrigin).get());
 
   // Create a thread to work with cdm.
   if (!mOwnerThread) {
diff --git a/dom/media/eme/mediadrm/MediaDrmCDMProxy.h b/dom/media/eme/mediadrm/MediaDrmCDMProxy.h
index f17735c75649..72b297acb397 100644
--- a/dom/media/eme/mediadrm/MediaDrmCDMProxy.h
+++ b/dom/media/eme/mediadrm/MediaDrmCDMProxy.h
@@ -37,8 +37,7 @@ public:
   void Init(PromiseId aPromiseId,
             const nsAString& aOrigin,
             const nsAString& aTopLevelOrigin,
-            const nsAString& aGMPName,
-            bool aInPrivateBrowsing) override;
+            const nsAString& aGMPName) override;
 
   void CreateSession(uint32_t aCreateSessionToken,
                      MediaKeySessionType aSessionType,
diff --git a/dom/media/gmp/GMPCDMProxy.cpp b/dom/media/gmp/GMPCDMProxy.cpp
index b6d6b40d679d..21a94dab9a55 100644
--- a/dom/media/gmp/GMPCDMProxy.cpp
+++ b/dom/media/gmp/GMPCDMProxy.cpp
@@ -54,16 +54,14 @@ void
 GMPCDMProxy::Init(PromiseId aPromiseId,
                   const nsAString& aOrigin,
                   const nsAString& aTopLevelOrigin,
-                  const nsAString& aGMPName,
-                  bool aInPrivateBrowsing)
+                  const nsAString& aGMPName)
 {
   MOZ_ASSERT(NS_IsMainThread());
   NS_ENSURE_TRUE_VOID(!mKeys.IsNull());
 
-  EME_LOG("GMPCDMProxy::Init (%s, %s) %s",
+  EME_LOG("GMPCDMProxy::Init (%s, %s)",
           NS_ConvertUTF16toUTF8(aOrigin).get(),
-          NS_ConvertUTF16toUTF8(aTopLevelOrigin).get(),
-          (aInPrivateBrowsing ? "PrivateBrowsing" : "NonPrivateBrowsing"));
+          NS_ConvertUTF16toUTF8(aTopLevelOrigin).get());
 
   nsCString pluginVersion;
   if (!mOwnerThread) {
@@ -93,7 +91,6 @@ GMPCDMProxy::Init(PromiseId aPromiseId,
   data->mOrigin = aOrigin;
   data->mTopLevelOrigin = aTopLevelOrigin;
   data->mGMPName = aGMPName;
-  data->mInPrivateBrowsing = aInPrivateBrowsing;
   data->mCrashHelper = mCrashHelper;
   nsCOMPtr<nsIRunnable> task(
     NewRunnableMethod<UniquePtr<InitData>&&>(this,
@@ -210,7 +207,6 @@ GMPCDMProxy::gmp_Init(UniquePtr<InitData>&& aData)
   nsresult rv = mps->GetNodeId(data.mOrigin,
                                data.mTopLevelOrigin,
                                data.mGMPName,
-                               data.mInPrivateBrowsing,
                                Move(callback));
   if (NS_FAILED(rv)) {
     RejectPromise(data.mPromiseId, NS_ERROR_DOM_INVALID_STATE_ERR,
@@ -241,10 +237,9 @@ GMPCDMProxy::gmp_InitGetGMPDecryptor(nsresult aResult,
     return;
   }
 
-  EME_LOG("GMPCDMProxy::gmp_Init (%s, %s) %s NodeId=%s",
+  EME_LOG("GMPCDMProxy::gmp_Init (%s, %s) NodeId=%s",
           NS_ConvertUTF16toUTF8(aData->mOrigin).get(),
           NS_ConvertUTF16toUTF8(aData->mTopLevelOrigin).get(),
-          (aData->mInPrivateBrowsing ? "PrivateBrowsing" : "NonPrivateBrowsing"),
           GetNodeId().get());
 
   nsTArray<nsCString> tags;
diff --git a/dom/media/gmp/GMPCDMProxy.h b/dom/media/gmp/GMPCDMProxy.h
index 646b6025a53d..d91de4acd895 100644
--- a/dom/media/gmp/GMPCDMProxy.h
+++ b/dom/media/gmp/GMPCDMProxy.h
@@ -31,8 +31,7 @@ public:
   void Init(PromiseId aPromiseId,
             const nsAString& aOrigin,
             const nsAString& aTopLevelOrigin,
-            const nsAString& aGMPName,
-            bool aInPrivateBrowsing) override;
+            const nsAString& aGMPName) override;
 
   void OnSetDecryptorId(uint32_t aId) override;
 
@@ -123,7 +122,6 @@ private:
     nsString mTopLevelOrigin;
     nsString mGMPName;
     RefPtr<GMPCrashHelper> mCrashHelper;
-    bool mInPrivateBrowsing;
   };
 
   // GMP thread only.
diff --git a/dom/media/gmp/GMPServiceChild.cpp b/dom/media/gmp/GMPServiceChild.cpp
index f79d5a700bee..9e7d9efe63c5 100644
--- a/dom/media/gmp/GMPServiceChild.cpp
+++ b/dom/media/gmp/GMPServiceChild.cpp
@@ -235,7 +235,6 @@ NS_IMETHODIMP
 GeckoMediaPluginServiceChild::GetNodeId(const nsAString& aOrigin,
                                         const nsAString& aTopLevelOrigin,
                                         const nsAString& aGMPName,
-                                        bool aInPrivateBrowsing,
                                         UniquePtr<GetNodeIdCallback>&& aCallback)
 {
   MOZ_ASSERT(NS_GetCurrentThread() == mGMPThread);
@@ -245,14 +244,12 @@ GeckoMediaPluginServiceChild::GetNodeId(const nsAString& aOrigin,
   nsString origin(aOrigin);
   nsString topLevelOrigin(aTopLevelOrigin);
   nsString gmpName(aGMPName);
-  bool pb = aInPrivateBrowsing;
   GetServiceChild()->Then(thread, __func__,
-    [rawCallback, origin, topLevelOrigin, gmpName, pb](GMPServiceChild* child) {
+    [rawCallback, origin, topLevelOrigin, gmpName](GMPServiceChild* child) {
       UniquePtr<GetNodeIdCallback> callback(rawCallback);
       nsCString outId;
       if (!child->SendGetGMPNodeId(origin, topLevelOrigin,
-                                   gmpName,
-                                   pb, &outId)) {
+                                   gmpName, &outId)) {
         callback->Done(NS_ERROR_FAILURE, EmptyCString());
         return;
       }
diff --git a/dom/media/gmp/GMPServiceChild.h b/dom/media/gmp/GMPServiceChild.h
index 9b5eab9af734..19da05c0767d 100644
--- a/dom/media/gmp/GMPServiceChild.h
+++ b/dom/media/gmp/GMPServiceChild.h
@@ -32,7 +32,6 @@ public:
   NS_IMETHOD GetNodeId(const nsAString& aOrigin,
                        const nsAString& aTopLevelOrigin,
                        const nsAString& aGMPName,
-                       bool aInPrivateBrowsingMode,
                        UniquePtr<GetNodeIdCallback>&& aCallback) override;
 
   NS_DECL_NSIOBSERVER
diff --git a/dom/media/gmp/GMPServiceParent.cpp b/dom/media/gmp/GMPServiceParent.cpp
index 0fad677c4be0..dea4e36aa957 100644
--- a/dom/media/gmp/GMPServiceParent.cpp
+++ b/dom/media/gmp/GMPServiceParent.cpp
@@ -1388,14 +1388,12 @@ nsresult
 GeckoMediaPluginServiceParent::GetNodeId(const nsAString& aOrigin,
                                          const nsAString& aTopLevelOrigin,
                                          const nsAString& aGMPName,
-                                         bool aInPrivateBrowsing,
                                          nsACString& aOutId)
 {
   MOZ_ASSERT(NS_GetCurrentThread() == mGMPThread);
-  LOGD(("%s::%s: (%s, %s), %s", __CLASS__, __FUNCTION__,
+  LOGD(("%s::%s: (%s, %s)", __CLASS__, __FUNCTION__,
        NS_ConvertUTF16toUTF8(aOrigin).get(),
-       NS_ConvertUTF16toUTF8(aTopLevelOrigin).get(),
-       (aInPrivateBrowsing ? "PrivateBrowsing" : "NonPrivateBrowsing")));
+       NS_ConvertUTF16toUTF8(aTopLevelOrigin).get()));
 
   nsresult rv;
 
@@ -1421,7 +1419,7 @@ GeckoMediaPluginServiceParent::GetNodeId(const nsAString& aOrigin,
   const uint32_t hash = AddToHash(HashString(aOrigin),
                                   HashString(aTopLevelOrigin));
 
-  if (aInPrivateBrowsing) {
+  if (OriginAttributes::IsPrivateBrowsing(NS_ConvertUTF16toUTF8(aOrigin))) {
     // For PB mode, we store the node id, indexed by the origin pair and GMP name,
     // so that if the same origin pair is opened for the same GMP in this session,
     // it gets the same node id.
@@ -1551,11 +1549,10 @@ NS_IMETHODIMP
 GeckoMediaPluginServiceParent::GetNodeId(const nsAString& aOrigin,
                                          const nsAString& aTopLevelOrigin,
                                          const nsAString& aGMPName,
-                                         bool aInPrivateBrowsing,
                                          UniquePtr<GetNodeIdCallback>&& aCallback)
 {
   nsCString nodeId;
-  nsresult rv = GetNodeId(aOrigin, aTopLevelOrigin, aGMPName, aInPrivateBrowsing, nodeId);
+  nsresult rv = GetNodeId(aOrigin, aTopLevelOrigin, aGMPName, nodeId);
   aCallback->Done(rv, nodeId);
   return rv;
 }
@@ -2010,11 +2007,9 @@ mozilla::ipc::IPCResult
 GMPServiceParent::RecvGetGMPNodeId(const nsString& aOrigin,
                                    const nsString& aTopLevelOrigin,
                                    const nsString& aGMPName,
-                                   const bool& aInPrivateBrowsing,
                                    nsCString* aID)
 {
-  nsresult rv = mService->GetNodeId(aOrigin, aTopLevelOrigin, aGMPName,
-                                    aInPrivateBrowsing, *aID);
+  nsresult rv = mService->GetNodeId(aOrigin, aTopLevelOrigin, aGMPName, *aID);
   if (!NS_SUCCEEDED(rv)) {
     return IPC_FAIL_NO_REASON(this);
   }
diff --git a/dom/media/gmp/GMPServiceParent.h b/dom/media/gmp/GMPServiceParent.h
index 5cb3cde1a276..a06792e636c1 100644
--- a/dom/media/gmp/GMPServiceParent.h
+++ b/dom/media/gmp/GMPServiceParent.h
@@ -44,7 +44,6 @@ public:
   NS_IMETHOD GetNodeId(const nsAString& aOrigin,
                        const nsAString& aTopLevelOrigin,
                        const nsAString& aGMPName,
-                       bool aInPrivateBrowsingMode,
                        UniquePtr<GetNodeIdCallback>&& aCallback) override;
 
   NS_DECL_MOZIGECKOMEDIAPLUGINCHROMESERVICE
@@ -90,8 +89,7 @@ private:
                                                    size_t* aOutPluginIndex);
 
   nsresult GetNodeId(const nsAString& aOrigin, const nsAString& aTopLevelOrigin,
-                     const nsAString& aGMPName,
-                     bool aInPrivateBrowsing, nsACString& aOutId);
+                     const nsAString& aGMPName, nsACString& aOutId);
 
   void UnloadPlugins();
   void CrashPlugins();
@@ -250,7 +248,6 @@ public:
   mozilla::ipc::IPCResult RecvGetGMPNodeId(const nsString& aOrigin,
                                            const nsString& aTopLevelOrigin,
                                            const nsString& aGMPName,
-                                           const bool& aInPrivateBrowsing,
                                            nsCString* aID) override;
   void ActorDestroy(ActorDestroyReason aWhy) override;
 
diff --git a/dom/media/gmp/PGMPService.ipdl b/dom/media/gmp/PGMPService.ipdl
index 413bf86d2f68..4bd01603a2b7 100644
--- a/dom/media/gmp/PGMPService.ipdl
+++ b/dom/media/gmp/PGMPService.ipdl
@@ -22,9 +22,7 @@ parent:
                  ProcessId[] alreadyBridgedTo)
     returns (uint32_t pluginId, ProcessId id, nsCString displayName, nsresult aResult);
 
-  sync GetGMPNodeId(nsString origin, nsString topLevelOrigin,
-                    nsString gmpName,
-                    bool inPrivateBrowsing)
+  sync GetGMPNodeId(nsString origin, nsString topLevelOrigin, nsString gmpName)
     returns (nsCString id);
 };
 
diff --git a/dom/media/gmp/mozIGeckoMediaPluginService.idl b/dom/media/gmp/mozIGeckoMediaPluginService.idl
index b9f1efc6944f..e625b5046934 100644
--- a/dom/media/gmp/mozIGeckoMediaPluginService.idl
+++ b/dom/media/gmp/mozIGeckoMediaPluginService.idl
@@ -161,12 +161,11 @@ interface mozIGeckoMediaPluginService : nsISupports
                        in GetGMPDecryptorCallback callback);
 
   /**
-   * Gets the NodeId for a (origin, urlbarOrigin, isInprivateBrowsing) tuple.
+   * Gets the NodeId for a (origin, urlbarOrigin) pair.
    */
   [noscript]
   void getNodeId(in AString origin,
                  in AString topLevelOrigin,
                  in AString gmpName,
-                 in bool inPrivateBrowsingMode,
                  in GetNodeIdCallback callback);
 };
diff --git a/dom/media/gtest/TestGMPCrossOrigin.cpp b/dom/media/gtest/TestGMPCrossOrigin.cpp
index 0344b3d6fd04..ef3b9c13c630 100644
--- a/dom/media/gtest/TestGMPCrossOrigin.cpp
+++ b/dom/media/gtest/TestGMPCrossOrigin.cpp
@@ -473,12 +473,26 @@ GetNodeId(const nsAString& aOrigin,
   nsresult result;
   UniquePtr<GetNodeIdCallback> callback(new TestGetNodeIdCallback(nodeId,
                                                                   result));
+
+  PrincipalOriginAttributes attrs;
+  attrs.mPrivateBrowsingId = aInPBMode ? 1 : 0;
+
+  nsAutoCString suffix;
+  attrs.CreateSuffix(suffix);
+
+  nsAutoString origin;
+  origin.Assign(aOrigin);
+  origin.Append(NS_ConvertUTF8toUTF16(suffix));
+
+  nsAutoString topLevelOrigin;
+  topLevelOrigin.Assign(aTopLevelOrigin);
+  topLevelOrigin.Append(NS_ConvertUTF8toUTF16(suffix));
+
   // We rely on the fact that the GetNodeId implementation for
   // GeckoMediaPluginServiceParent is synchronous.
-  nsresult rv = service->GetNodeId(aOrigin,
-                                   aTopLevelOrigin,
+  nsresult rv = service->GetNodeId(origin,
+                                   topLevelOrigin,
                                    NS_LITERAL_STRING("gmp-fake"),
-                                   aInPBMode,
                                    Move(callback));
   EXPECT_TRUE(NS_SUCCEEDED(rv) && NS_SUCCEEDED(result));
   return nodeId;
diff --git a/dom/media/systemservices/MediaChild.cpp b/dom/media/systemservices/MediaChild.cpp
index 262dbcf5d1b3..c01e6249d2c3 100644
--- a/dom/media/systemservices/MediaChild.cpp
+++ b/dom/media/systemservices/MediaChild.cpp
@@ -20,7 +20,7 @@ namespace mozilla {
 namespace media {
 
 already_AddRefed<Pledge<nsCString>>
-GetOriginKey(const nsCString& aOrigin, bool aPrivateBrowsing, bool aPersist)
+GetOriginKey(const nsCString& aOrigin, bool aPersist)
 {
   RefPtr<MediaManager> mgr = MediaManager::GetInstance();
   MOZ_ASSERT(mgr);
@@ -29,10 +29,9 @@ GetOriginKey(const nsCString& aOrigin, bool aPrivateBrowsing, bool aPersist)
   uint32_t id = mgr->mGetOriginKeyPledges.Append(*p);
 
   if (XRE_GetProcessType() == GeckoProcessType_Default) {
-    mgr->GetNonE10sParent()->RecvGetOriginKey(id, aOrigin, aPrivateBrowsing,
-                                              aPersist);
+    mgr->GetNonE10sParent()->RecvGetOriginKey(id, aOrigin, aPersist);
   } else {
-    Child::Get()->SendGetOriginKey(id, aOrigin, aPrivateBrowsing, aPersist);
+    Child::Get()->SendGetOriginKey(id, aOrigin, aPersist);
   }
   return p.forget();
 }
diff --git a/dom/media/systemservices/MediaChild.h b/dom/media/systemservices/MediaChild.h
index f44e1e42642e..3e7f9158e72c 100644
--- a/dom/media/systemservices/MediaChild.h
+++ b/dom/media/systemservices/MediaChild.h
@@ -25,7 +25,7 @@ namespace media {
 // (promise-like objects) with the future value. Use pledge.Then(func) to access.
 
 already_AddRefed<Pledge<nsCString>>
-GetOriginKey(const nsCString& aOrigin, bool aPrivateBrowsing, bool aPersist);
+GetOriginKey(const nsCString& aOrigin, bool aPersist);
 
 void
 SanitizeOriginKeys(const uint64_t& aSinceWhen, bool aOnlyPrivateBrowsing);
diff --git a/dom/media/systemservices/MediaParent.cpp b/dom/media/systemservices/MediaParent.cpp
index 3d69ab18f9db..42aa33bd8ed9 100644
--- a/dom/media/systemservices/MediaParent.cpp
+++ b/dom/media/systemservices/MediaParent.cpp
@@ -369,7 +369,6 @@ bool NonE10s::SendGetOriginKeyResponse(const uint32_t& aRequestId,
 template<class Super> mozilla::ipc::IPCResult
 Parent<Super>::RecvGetOriginKey(const uint32_t& aRequestId,
                                 const nsCString& aOrigin,
-                                const bool& aPrivateBrowsing,
                                 const bool& aPersist)
 {
   MOZ_ASSERT(NS_IsMainThread());
@@ -395,11 +394,12 @@ Parent<Super>::RecvGetOriginKey(const uint32_t& aRequestId,
   RefPtr<Parent<Super>> that(this);
 
   rv = sts->Dispatch(NewRunnableFrom([this, that, id, profileDir, aOrigin,
-                                      aPrivateBrowsing, aPersist]() -> nsresult {
+                                      aPersist]() -> nsresult {
     MOZ_ASSERT(!NS_IsMainThread());
     mOriginKeyStore->mOriginKeys.SetProfileDir(profileDir);
-    nsCString result;
-    if (aPrivateBrowsing) {
+
+    nsAutoCString result;
+    if (OriginAttributes::IsPrivateBrowsing(aOrigin)) {
       mOriginKeyStore->mPrivateBrowsingOriginKeys.GetOriginKey(aOrigin, result);
     } else {
       mOriginKeyStore->mOriginKeys.GetOriginKey(aOrigin, result, aPersist);
diff --git a/dom/media/systemservices/MediaParent.h b/dom/media/systemservices/MediaParent.h
index cc127c0a10b1..aa242954f12d 100644
--- a/dom/media/systemservices/MediaParent.h
+++ b/dom/media/systemservices/MediaParent.h
@@ -29,7 +29,6 @@ public:
 protected:
   virtual mozilla::ipc::IPCResult RecvGetOriginKey(const uint32_t& aRequestId,
                                                    const nsCString& aOrigin,
-                                                   const bool& aPrivateBrowsing,
                                                    const bool& aPersist) = 0;
   virtual mozilla::ipc::IPCResult RecvSanitizeOriginKeys(const uint64_t& aSinceWhen,
                                                          const bool& aOnlyPrivateBrowsing) = 0;
@@ -52,7 +51,6 @@ public:
 
   virtual mozilla::ipc::IPCResult RecvGetOriginKey(const uint32_t& aRequestId,
                                                    const nsCString& aOrigin,
-                                                   const bool& aPrivateBrowsing,
                                                    const bool& aPersist) override;
   virtual mozilla::ipc::IPCResult RecvSanitizeOriginKeys(const uint64_t& aSinceWhen,
                                                          const bool& aOnlyPrivateBrowsing) override;
diff --git a/dom/media/systemservices/PMedia.ipdl b/dom/media/systemservices/PMedia.ipdl
index c060f030eb40..23682d2a1297 100644
--- a/dom/media/systemservices/PMedia.ipdl
+++ b/dom/media/systemservices/PMedia.ipdl
@@ -18,18 +18,19 @@ parent:
    * This is needed by mediaDevices.enumerateDevices() to produce persistent
    * deviceIds that wont work cross-origin.
    *
-   * If aPrivateBrowsing is false, a key for this origin is returned from a
-   * primary pool of temporal in-memory keys and persistent keys read from disk.
-   * If no key exists, a temporal one is created.
+   * The origin string must contain the OriginAttributes suffix.
+   * If this OriginAttributes dictionary has the privateBrowsing flag set to
+   * false, a key for this origin is returned from a primary pool of temporal
+   * in-memory keys and persistent keys read from disk. If no key exists, a
+   * temporal one is created.
    * If aPersist is true and key is temporal, the key is promoted to persistent.
    * Once persistent, a key cannot become temporal again.
    *
-   * If aPrivateBrowsing is true, a different key for this origin is returned
-   * from a secondary pool that is never persisted to disk, and aPersist is
-   * ignored.
+   * If the OriginAttributes dictionary has the privateBrowsing flag set to
+   * true, a different key for this origin is returned from a secondary pool
+   * that is never persisted to disk, and aPersist is ignored.
    */
-  async GetOriginKey(uint32_t aRequestId, nsCString aOrigin, bool aPrivateBrowsing,
-                     bool aPersist);
+  async GetOriginKey(uint32_t aRequestId, nsCString aOrigin, bool aPersist);
 
   /**
    * Clear per-orgin list of persistent deviceIds stored for enumerateDevices