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/MediaFormatReader.h

@@ -20,7 +20,9 @@
 
 namespace mozilla {
 
+#ifdef MOZ_EME
 class CDMProxy;
+#endif
 
 class MediaFormatReader final : public MediaDecoderReader
 {
@@ -91,7 +93,9 @@ public:
     return mTrackDemuxersMayBlock;
   }
 
+#ifdef MOZ_EME
   void SetCDMProxy(CDMProxy* aProxy) override;
+#endif
 
   // Returns a string describing the state of the decoder data.
   // Used for debugging purposes.
@@ -584,7 +588,9 @@ private:
   RefPtr<VideoFrameContainer> mVideoFrameContainer;
   layers::ImageContainer* GetImageContainer();
 
+#ifdef MOZ_EME
   RefPtr<CDMProxy> mCDMProxy;
+#endif
 
   RefPtr<GMPCrashHelper> mCrashHelper;