Bug 1307019 - Ensure MDSM and MFR have consistent view of what counts as encrypted. r=jya The patch in bug 1300069 introduced an inconsistency between what the MediaDecoderStateMachine and the MediaFormatReader consider an encrypted stream. The MDSM considered a stream encrypted if mInfo.IsEncrypted() is true, and that only takes into account the PSSH. Whereas the MFR only considers the presence of a TENC box to indicate encryptedness. This would cause the MDSM to not wait for the CDM before trying to start decoding. So if you setup the MediaSource before setting the MediaKeys on the MediaElement, you'll end up trying to create an EME decoder without a CDMProxy, and that causes a null pointer deref and crash. This patch ensures that the MDSM and the MFR use the same logic to determine whether a stream is encrypted. MozReview-Commit-ID: KGuYTuP9XDL

--- a/dom/media/MediaInfo.h
+++ b/dom/media/MediaInfo.h
@@ -459,17 +459,18 @@ public:
     // Set dummy values so that HasAudio() will return true;
     // See AudioInfo::IsValid()
     mAudio.mChannels = 2;
     mAudio.mRate = 44100;
   }
 
   bool IsEncrypted() const
   {
-    return mCrypto.IsEncrypted();
+    return (HasAudio() && mAudio.mCrypto.mValid) ||
+           (HasVideo() && mVideo.mCrypto.mValid);
   }
 
   bool HasValidMedia() const
   {
     return HasVideo() || HasAudio();
   }
 
   void AssertValid() const