| Index: media/base/key_systems.cc | 
| diff --git a/media/base/key_systems.cc b/media/base/key_systems.cc | 
| index 4dee18a97ee5413bf527431b7c93ba5c6bf90e31..27bd0877d16d5fcd34d72d9f3624f3a8833aaab3 100644 | 
| --- a/media/base/key_systems.cc | 
| +++ b/media/base/key_systems.cc | 
| @@ -57,8 +57,8 @@ static const NamedCodec kCodecStrings[] = { | 
| {"vp8.0", EME_CODEC_WEBM_VP8},      // VP8. | 
| {"vp9", EME_CODEC_WEBM_VP9},        // VP9. | 
| {"vp9.0", EME_CODEC_WEBM_VP9},      // VP9. | 
| +    {"vp09", EME_CODEC_COMMON_VP9},     // New multi-part VP9 for WebM and MP4. | 
| #if BUILDFLAG(USE_PROPRIETARY_CODECS) | 
| -    {"vp09", EME_CODEC_MP4_VP9},   // VP9 in MP4. | 
| {"mp4a", EME_CODEC_MP4_AAC},   // AAC. | 
| {"avc1", EME_CODEC_MP4_AVC1},  // AVC1. | 
| {"avc3", EME_CODEC_MP4_AVC1},  // AVC3. | 
| @@ -599,15 +599,21 @@ EmeConfigRule KeySystemsImpl::GetContentTypeConfigRule( | 
| // necessary because |codecs| may be empty.) | 
| SupportedCodecs mime_type_codec_mask = | 
| GetCodecMaskForMimeType(container_mime_type); | 
| -  if ((key_system_codec_mask & mime_type_codec_mask) == 0) | 
| +  if ((key_system_codec_mask & mime_type_codec_mask) == 0) { | 
| +    DVLOG(2) << " Container " << container_mime_type << " not supported by " | 
| +             << key_system; | 
| return EmeConfigRule::NOT_SUPPORTED; | 
| +  } | 
|  | 
| // Check that the codecs are supported by the key system and container. | 
| EmeConfigRule support = EmeConfigRule::SUPPORTED; | 
| for (size_t i = 0; i < codecs.size(); i++) { | 
| SupportedCodecs codec = GetCodecForString(codecs[i]); | 
| -    if ((codec & key_system_codec_mask & mime_type_codec_mask) == 0) | 
| +    if ((codec & key_system_codec_mask & mime_type_codec_mask) == 0) { | 
| +      DVLOG(2) << " Container/codec pair (" << container_mime_type << " / " | 
| +               << codecs[i] << ") not supported by " << key_system; | 
| return EmeConfigRule::NOT_SUPPORTED; | 
| +    } | 
| #if defined(OS_ANDROID) | 
| // Check whether the codec supports a hardware-secure mode. The goal is to | 
| // prevent mixing of non-hardware-secure codecs with hardware-secure codecs, | 
|  |