Bug 1524049 - pref on Vorbis decoding on RDD for Windows. r=drno

Also, make sure it is disabled for MinGW builds because of Bug
1597408.

Differential Revision: https://phabricator.services.mozilla.com/D53286

--HG--
extra : moz-landing-system : lando

dom/media/ipc/RemoteDecoderModule.cpp

@@ -44,9 +44,17 @@ bool RemoteDecoderModule::SupportsMimeType(
     supports |= AOMDecoder::IsAV1(aMimeType);
   }
 #endif
+#if !defined(__MINGW32__)
+  // We can't let RDD handle the decision to support Vorbis decoding on
+  // MinGW builds because of Bug 1597408 (Vorbis decoding on RDD causing
+  // sandboxing failure on MinGW-clang).  Typically this would be dealt
+  // with using defines in StaticPrefList.yaml, but we must handle it
+  // here because of Bug 1598426 (the __MINGW32__ define isn't supported
+  // in StaticPrefList.yaml).
   if (StaticPrefs::media_rdd_vorbis_enabled()) {
     supports |= VorbisDataDecoder::IsVorbis(aMimeType);
   }
+#endif
   if (StaticPrefs::media_rdd_wav_enabled()) {
     supports |= WaveDataDecoder::IsWave(aMimeType);
   }

dom/media/platforms/agnostic/AgnosticDecoderModule.cpp

@@ -24,11 +24,22 @@ bool AgnosticDecoderModule::SupportsMimeType(
     const nsACString& aMimeType, DecoderDoctorDiagnostics* aDiagnostics) const {
   bool supports =
       VPXDecoder::IsVPX(aMimeType) || TheoraDecoder::IsTheora(aMimeType);
+#if defined(__MINGW32__)
+  // If this is a MinGW build we need to force AgnosticDecoderModule to
+  // handle the decision to support Vorbis decoding (instead of
+  // RDD/RemoteDecoderModule) because of Bug 1597408 (Vorbis decoding on
+  // RDD causing sandboxing failure on MinGW-clang).  Typically this
+  // would be dealt with using defines in StaticPrefList.yaml, but we
+  // must handle it here because of Bug 1598426 (the __MINGW32__ define
+  // isn't supported in StaticPrefList.yaml).
+  supports |= VorbisDataDecoder::IsVorbis(aMimeType);
+#else
   if (!StaticPrefs::media_rdd_vorbis_enabled() ||
       !StaticPrefs::media_rdd_process_enabled() ||
       !BrowserTabsRemoteAutostart()) {
     supports |= VorbisDataDecoder::IsVorbis(aMimeType);
   }
+#endif
   if (!StaticPrefs::media_rdd_wav_enabled() ||
       !StaticPrefs::media_rdd_process_enabled() ||
       !BrowserTabsRemoteAutostart()) {

modules/libpref/init/StaticPrefList.yaml

@@ -5811,6 +5811,8 @@
   value: true
 #elif defined(XP_MACOSX)
   value: true
+#elif defined(XP_WIN) && !defined(_ARM64_)
+  value: true
 #else
   value: false
 #endif