diff --git a/dom/plugins/base/nsNPAPIPlugin.cpp b/dom/plugins/base/nsNPAPIPlugin.cpp
index 920b1099ef42..7c2f622c1c83 100644
--- a/dom/plugins/base/nsNPAPIPlugin.cpp
+++ b/dom/plugins/base/nsNPAPIPlugin.cpp
@@ -2402,6 +2402,27 @@ _setvalue(NPP npp, NPPVariable variable, void *result)
       return inst->SetUsesDOMForCursor(useDOMForCursor);
     }
 
+    case NPPVpluginIsPlayingAudio: {
+      // For testing, remove me
+      printf("set audio %p\n", result);
+      bool isPlaying = !!result;
+
+      nsCOMPtr<nsIDocument> doc = GetDocumentFromNPP(npp);
+      if (doc) {
+        nsCOMPtr<nsPIDOMWindow> domwindow = doc->GetWindow();
+        nsCOMPtr<nsIObserverService> observerService =
+          services::GetObserverService();
+        if (observerService) {
+          // XXX THIS NEEDS A BETTER API
+          observerService->NotifyObservers(ToSupports(domwindow),
+                                           "media-playback",
+                                           isPlaying ? NS_LITERAL_STRING("active").get() :
+                                                       NS_LITERAL_STRING("inactive").get());
+        }
+      }
+      return NPERR_NO_ERROR;
+    }
+
 #ifndef MOZ_WIDGET_ANDROID
     // On android, their 'drawing model' uses the same constant!
     case NPPVpluginDrawingModel: {
diff --git a/dom/plugins/ipc/PPluginInstance.ipdl b/dom/plugins/ipc/PPluginInstance.ipdl
index 3a4a3d521da9..8db84097b6c1 100644
--- a/dom/plugins/ipc/PPluginInstance.ipdl
+++ b/dom/plugins/ipc/PPluginInstance.ipdl
@@ -150,6 +150,8 @@ parent:
     returns (NPError result);
   intr NPN_SetValue_NPPVpluginEventModel(int eventModel)
     returns (NPError result);
+  intr NPN_SetValue_NPPVpluginIsPlayingAudio(bool isAudioPlaying)
+    returns (NPError result);
 
   intr NPN_GetURL(nsCString url, nsCString target)
     returns (NPError result);
diff --git a/dom/plugins/ipc/PluginInstanceChild.cpp b/dom/plugins/ipc/PluginInstanceChild.cpp
index 512db7dba2c9..87b574f3deb9 100644
--- a/dom/plugins/ipc/PluginInstanceChild.cpp
+++ b/dom/plugins/ipc/PluginInstanceChild.cpp
@@ -626,6 +626,14 @@ PluginInstanceChild::NPN_SetValue(NPPVariable aVar, void* aValue)
     }
 #endif
 
+    case NPPVpluginIsPlayingAudio: {
+        NPError rv = NPERR_GENERIC_ERROR;
+        if (!CallNPN_SetValue_NPPVpluginIsPlayingAudio((NPBool)(intptr_t)aValue, &rv)) {
+            return NPERR_GENERIC_ERROR;
+        }
+        return rv;
+    }
+
     default:
         MOZ_LOG(GetPluginLog(), LogLevel::Warning,
                ("In PluginInstanceChild::NPN_SetValue: Unhandled NPPVariable %i (%s)",
diff --git a/dom/plugins/ipc/PluginInstanceParent.cpp b/dom/plugins/ipc/PluginInstanceParent.cpp
index 45c012c40b92..bfaa5061803c 100644
--- a/dom/plugins/ipc/PluginInstanceParent.cpp
+++ b/dom/plugins/ipc/PluginInstanceParent.cpp
@@ -440,6 +440,15 @@ PluginInstanceParent::AnswerNPN_SetValue_NPPVpluginEventModel(
 #endif
 }
 
+bool
+PluginInstanceParent::AnswerNPN_SetValue_NPPVpluginIsPlayingAudio(
+    const bool& isAudioPlaying, NPError* result)
+{
+    *result = mNPNIface->setvalue(mNPP, NPPVpluginIsPlayingAudio,
+                                  (void*)(intptr_t)isAudioPlaying);
+    return true;
+}
+
 bool
 PluginInstanceParent::AnswerNPN_GetURL(const nsCString& url,
                                        const nsCString& target,
diff --git a/dom/plugins/ipc/PluginInstanceParent.h b/dom/plugins/ipc/PluginInstanceParent.h
index 052408528f17..80af054cf936 100644
--- a/dom/plugins/ipc/PluginInstanceParent.h
+++ b/dom/plugins/ipc/PluginInstanceParent.h
@@ -128,6 +128,9 @@ public:
     virtual bool
     AnswerNPN_SetValue_NPPVpluginEventModel(const int& eventModel,
                                              NPError* result) override;
+    virtual bool
+    AnswerNPN_SetValue_NPPVpluginIsPlayingAudio(const bool& isAudioPlaying,
+                                                NPError* result) override;
 
     virtual bool
     AnswerNPN_GetURL(const nsCString& url, const nsCString& target,