Bug 1178680 - Remove MediaDecoder::Observe as we have MediaShutdownManager. r=cpearce.

dom/media/MediaDecoder.cpp

@@ -141,7 +141,7 @@ MediaDecoder::InitStatics()
 
 NS_IMPL_ISUPPORTS(MediaMemoryTracker, nsIMemoryReporter)
 
-NS_IMPL_ISUPPORTS(MediaDecoder, nsIObserver)
+NS_IMPL_ISUPPORTS0(MediaDecoder)
 
 void MediaDecoder::NotifyOwnerActivityChanged()
 {
@@ -812,18 +812,6 @@ void MediaDecoder::PlaybackEnded()
   }
 }
 
-NS_IMETHODIMP MediaDecoder::Observe(nsISupports *aSubjet,
-                                        const char *aTopic,
-                                        const char16_t *someData)
-{
-  MOZ_ASSERT(NS_IsMainThread());
-  if (strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0) {
-    Shutdown();
-  }
-
-  return NS_OK;
-}
-
 MediaDecoder::Statistics
 MediaDecoder::GetStatistics()
 {

dom/media/MediaDecoder.h

@@ -277,7 +277,6 @@ public:
   typedef MediaPromise<SeekResolveValue, bool /* aIgnored */, /* IsExclusive = */ true> SeekPromise;
 
   NS_DECL_THREADSAFE_ISUPPORTS
-  NS_DECL_NSIOBSERVER
 
   // Enumeration for the valid play states (see mPlayState)
   enum PlayState {