--- a/dom/base/Navigator.cpp
+++ b/dom/base/Navigator.cpp
@@ -64,16 +64,17 @@
 #include "nsComponentManagerUtils.h"
 #include "nsIStringStream.h"
 #include "nsIHttpChannel.h"
 #include "nsIHttpChannelInternal.h"
 #include "TimeManager.h"
 #include "nsStreamUtils.h"
 #include "WidgetUtils.h"
 #include "nsIPresentationService.h"
+#include "nsIScriptError.h"
 
 #include "mozilla/dom/MediaDevices.h"
 #include "MediaManager.h"
 
 #include "nsIDOMGlobalPropertyInitializer.h"
 #include "nsJSUtils.h"
 
 #include "nsScriptNameSpaceManager.h"
@@ -90,16 +91,17 @@
 
 #if defined(XP_LINUX)
 #include "mozilla/Hal.h"
 #endif
 #include "mozilla/dom/ContentChild.h"
 
 #include "mozilla/EMEUtils.h"
 #include "mozilla/DetailedPromise.h"
+#include "mozilla/Unused.h"
 
 namespace mozilla {
 namespace dom {
 
 static bool sVibratorEnabled   = false;
 static uint32_t sMaxVibrateMS  = 0;
 static uint32_t sMaxVibrateListLen = 0;
 static const char* kVibrationPermissionType = "vibration";
@@ -2019,16 +2021,32 @@ Navigator::RequestMediaKeySystemAccess(c
   EME_LOG("%s",
           RequestKeySystemAccessLogString(
             aKeySystem, aConfigs, mWindow->IsSecureContext())
             .get());
 
   Telemetry::Accumulate(Telemetry::MEDIA_EME_SECURE_CONTEXT,
                         mWindow->IsSecureContext());
 
+  if (!mWindow->IsSecureContext()) {
+    nsIDocument* doc = mWindow->GetExtantDoc();
+    nsString uri;
+    if (doc) {
+      Unused << doc->GetDocumentURI(uri);
+    }
+    const char16_t* params[] = { uri.get() };
+    nsContentUtils::ReportToConsole(nsIScriptError::warningFlag,
+                                    NS_LITERAL_CSTRING("Media"),
+                                    doc,
+                                    nsContentUtils::eDOM_PROPERTIES,
+                                    "MediaEMEInsecureContextDeprecatedWarning",
+                                    params,
+                                    ArrayLength(params));
+  }
+
   nsCOMPtr<nsIGlobalObject> go = do_QueryInterface(mWindow);
   RefPtr<DetailedPromise> promise =
     DetailedPromise::Create(go, aRv,
       NS_LITERAL_CSTRING("navigator.requestMediaKeySystemAccess"),
       Telemetry::VIDEO_EME_REQUEST_SUCCESS_LATENCY_MS,
       Telemetry::VIDEO_EME_REQUEST_FAILURE_LATENCY_MS);
   if (aRv.Failed()) {
     return nullptr;

--- a/dom/locales/en-US/chrome/dom/dom.properties
+++ b/dom/locales/en-US/chrome/dom/dom.properties
@@ -140,16 +140,18 @@ MediaCannotPlayNoDecoders=Cannot play me
 MediaNoDecoders=No decoders for some of the requested formats: %S
 MediaCannotInitializePulseAudio=Unable to use PulseAudio
 # LOCALIZATION NOTE: Do not translate "MediaRecorder".
 MediaRecorderMultiTracksNotSupported=MediaRecorder does not support recording multiple tracks of the same type at this time.
 # LOCALIZATION NOTE: %S is the ID of the MediaStreamTrack passed to MediaStream.addTrack(). Do not translate "MediaStreamTrack" and "AudioChannel".
 MediaStreamAddTrackDifferentAudioChannel=MediaStreamTrack %S could not be added since it belongs to a different AudioChannel.
 # LOCALIZATION NOTE: Do not translate "MediaStream", "stop()" and "MediaStreamTrack"
 MediaStreamStopDeprecatedWarning=MediaStream.stop() is deprecated and will soon be removed. Use MediaStreamTrack.stop() instead.
+# LOCALIZATION NOTE: %S is the URL of the web page which is not served on HTTPS and thus is not encrypted and considered insecure.
+MediaEMEInsecureContextDeprecatedWarning=Using Encrypted Media Extensions at %S on an insecure (i.e. non-HTTPS) context is deprecated and will soon be removed. You should consider switching to a secure origin such as HTTPS.
 # LOCALIZATION NOTE: Do not translate "DOMException", "code" and "name"
 DOMExceptionCodeWarning=Use of DOMException’s code attribute is deprecated. Use name instead.
 # LOCALIZATION NOTE: Do not translate "__exposedProps__"
 NoExposedPropsWarning=Exposing chrome JS objects to content without __exposedProps__ is insecure and deprecated. See https://developer.mozilla.org/en/XPConnect_wrappers for more information.
 # LOCALIZATION NOTE: Do not translate "Mutation Event" and "MutationObserver"
 MutationEventWarning=Use of Mutation Events is deprecated. Use MutationObserver instead.
 # LOCALIZATION NOTE: Do not translate "Components"
 ComponentsWarning=The Components object is deprecated. It will soon be removed.