Bug 1288618 - Part 11: Add a pref to enable GPU process video decoding. r=cpearce

dom/media/MediaPrefs.h

@@ -101,6 +101,7 @@ private:
   DECL_MEDIA_PREF("media.gmp.async-shutdown-timeout",         GMPAsyncShutdownTimeout, uint32_t, GMP_DEFAULT_ASYNC_SHUTDOWN_TIMEOUT);
   DECL_MEDIA_PREF("media.eme.enabled",                        EMEEnabled, bool, false);
   DECL_MEDIA_PREF("media.use-blank-decoder",                  PDMUseBlankDecoder, bool, false);
+  DECL_MEDIA_PREF("media.gpu-process-decoder",                PDMUseGPUDecoder, bool, false);
 #ifdef MOZ_GONK_MEDIACODEC
   DECL_MEDIA_PREF("media.gonk.enabled",                       PDMGonkDecoderEnabled, bool, true);
 #endif