EME on Android: Improve accuracy of Key System availability.

media/base/media.h

Index: media/base/media.h
diff --git a/media/base/media.h b/media/base/media.h
index 65a7a69e0152b6ffe271ca3e57a0ca5b4c6259f3..b6cccc49f478dd6c6aabe3b4e2eedcd5fe444992 100644
--- a/media/base/media.h
+++ b/media/base/media.h
@@ -46,6 +46,12 @@ MEDIA_EXPORT bool IsUnifiedMediaPipelineEnabled();
 // cases where existing pipeline has no support). As above, codecs requiring
 // platform support may not be available.
 MEDIA_EXPORT bool IsUnifiedMediaPipelineEnabledForMse();
+
+// Returns whether the platform decoders are available for use.
+// This includes decoders being available on the platform and accessible, such
+// as via the GPU process. Should only be used for actual decoders
+// (e.g. MediaCodec) and not full-featured players (e.g. MediaPlayer).
+MEDIA_EXPORT bool ArePlatformDecodersAvailable();
 #endif
 
 }  // namespace media