Bug 1429009. P1 - notify 'DownloadProgressed' immediately to preserve the event order. r=bechen,gerald

We also need to call GetOwner()->UpdateReadyState() since mCanPlayThrough might
have changed.

MozReview-Commit-ID: C5djzu1sXqV

--HG--
extra : rebase_source : 1037cb7e1bf3a32fa60451e9a2a64ce63d06b8c2
extra : intermediate-source : 373c47f094dfb85ca2576d18a302d9ceb4e82ed5
extra : source : b710ff5026c18ac851be56ac9a369fe69b1d5b5d

dom/media/ChannelMediaDecoder.cpp

@@ -413,6 +413,8 @@ ChannelMediaDecoder::DownloadProgressed()
   MOZ_ASSERT(NS_IsMainThread());
   MOZ_DIAGNOSTIC_ASSERT(!IsShutdown());
 
+  GetOwner()->DownloadProgressed();
+
   using StatsPromise = MozPromise<MediaStatistics, bool, true>;
   InvokeAsync(GetStateMachine()->OwnerThread(),
               __func__,
@@ -438,7 +440,8 @@ ChannelMediaDecoder::DownloadProgressed()
         GetStateMachine()->DispatchCanPlayThrough(mCanPlayThrough);
         mResource->ThrottleReadahead(ShouldThrottleDownload(aStats));
         AbstractThread::AutoEnter context(AbstractMainThread());
-        GetOwner()->DownloadProgressed();
+        // Update readyState since mCanPlayThrough might have changed.
+        GetOwner()->UpdateReadyState();
       },
       []() { MOZ_ASSERT_UNREACHABLE("Promise not resolved"); });
 }