Issue #26 Part 2a: make more EME code conditional.

- Exclude missed MediaKey functions and CDMProxy code.
- Exclude EME APIs frm being built (webidl change)
- Fix tests in --disable-eme state

dom/media/platforms/PDMFactory.h

@@ -11,7 +11,9 @@
 #include "mozilla/Function.h"
 #include "mozilla/StaticMutex.h"
 
+#ifdef MOZ_EME
 class CDMProxy;
+#endif
 
 namespace mozilla {
 
@@ -38,12 +40,14 @@ public:
   bool Supports(const TrackInfo& aTrackInfo,
                 DecoderDoctorDiagnostics* aDiagnostics) const;
 
+#ifdef MOZ_EME
   // Creates a PlatformDecoderModule that uses a CDMProxy to decrypt or
   // decrypt-and-decode EME encrypted content. If the CDM only decrypts and
   // does not decode, we create a PDM and use that to create MediaDataDecoders
   // that we use on on aTaskQueue to decode the decrypted stream.
   // This is called on the decode task queue.
   void SetCDMProxy(CDMProxy* aProxy);
+#endif
 
   static constexpr int kYUV400 = 0;
   static constexpr int kYUV420 = 1;