--- a/dom/media/MediaManager.cpp
+++ b/dom/media/MediaManager.cpp
@@ -856,22 +856,35 @@ AudioDevice::GetType(nsAString& aType)
 
 NS_IMETHODIMP
 MediaDevice::GetId(nsAString& aID)
 {
   aID.Assign(mID);
   return NS_OK;
 }
 
+NS_IMETHODIMP
+MediaDevice::GetRawId(nsAString& aID)
+{
+  aID.Assign(mRawID);
+  return NS_OK;
+}
+
 void
 MediaDevice::SetId(const nsAString& aID)
 {
   mID.Assign(aID);
 }
 
+void
+MediaDevice::SetRawId(const nsAString& aID)
+{
+  mRawID.Assign(aID);
+}
+
 NS_IMETHODIMP
 MediaDevice::GetMediaSource(nsAString& aMediaSource)
 {
   if (mMediaSource == MediaSourceEnum::Microphone) {
     aMediaSource.Assign(NS_LITERAL_STRING("microphone"));
   } else if (mMediaSource == MediaSourceEnum::AudioCapture) {
     aMediaSource.Assign(NS_LITERAL_STRING("audioCapture"));
   } else if (mMediaSource == MediaSourceEnum::Window) { // this will go away
@@ -2437,16 +2450,17 @@ MediaManager::GetUserMedia(nsPIDOMWindow
 
 /* static */ void
 MediaManager::AnonymizeDevices(SourceSet& aDevices, const nsACString& aOriginKey)
 {
   if (!aOriginKey.IsEmpty()) {
     for (auto& device : aDevices) {
       nsString id;
       device->GetId(id);
+      device->SetRawId(id);
       AnonymizeId(id, aOriginKey);
       device->SetId(id);
     }
   }
 }
 
 /* static */ nsresult
 MediaManager::AnonymizeId(nsAString& aId, const nsACString& aOriginKey)

--- a/dom/media/MediaManager.h
+++ b/dom/media/MediaManager.h
@@ -64,16 +64,17 @@ class MediaDevice : public nsIMediaDevic
 {
 public:
   typedef MediaEngineSource Source;
 
   NS_DECL_THREADSAFE_ISUPPORTS
   NS_DECL_NSIMEDIADEVICE
 
   void SetId(const nsAString& aID);
+  void SetRawId(const nsAString& aID);
   virtual uint32_t GetBestFitnessDistance(
       const nsTArray<const NormalizedConstraintSet*>& aConstraintSets);
   virtual Source* GetSource() = 0;
   nsresult Allocate(const dom::MediaTrackConstraints &aConstraints,
                     const MediaEnginePrefs &aPrefs,
                     const nsACString& aOrigin,
                     const char** aOutBadConstraint);
   nsresult Restart(const dom::MediaTrackConstraints &aConstraints,
@@ -89,16 +90,17 @@ protected:
 private:
   static bool StringsContain(const dom::OwningStringOrStringSequence& aStrings,
                              nsString aN);
   static uint32_t FitnessDistance(nsString aN,
       const dom::ConstrainDOMStringParameters& aParams);
 protected:
   nsString mName;
   nsString mID;
+  nsString mRawID;
   dom::MediaSourceEnum mMediaSource;
   RefPtr<MediaEngineSource> mSource;
   RefPtr<MediaEngineSource::AllocationHandle> mAllocationHandle;
 public:
   dom::MediaSourceEnum GetMediaSource() {
     return mMediaSource;
   }
   bool mIsVideo;

--- a/dom/media/nsIDOMNavigatorUserMedia.idl
+++ b/dom/media/nsIDOMNavigatorUserMedia.idl
@@ -1,22 +1,23 @@
 /* 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/. */
 
 #include "nsISupports.idl"
 #include "nsIVariant.idl"
 
-[scriptable, builtinclass, uuid(cebcefca-2de1-460d-b253-d0582c50b40f)]
+[scriptable, builtinclass, uuid(ba3b2e08-1c07-4cd3-8822-f4d7e35ff2ae)]
 interface nsIMediaDevice : nsISupports
 {
   readonly attribute DOMString type;
   readonly attribute DOMString name;
   readonly attribute DOMString id;
   readonly attribute DOMString mediaSource;
+  readonly attribute DOMString rawId;
 };
 
 [scriptable, function, uuid(24544878-d35e-4962-8c5f-fb84e97bdfee)]
 interface nsIGetUserMediaDevicesSuccessCallback : nsISupports
 {
   void onSuccess(in nsIVariant devices);
 };