Add m-esr52 at 52.6.0

1 files changed, 1135 insertions, 0 deletions

diff --git a/dom/media/eme/MediaKeySystemAccess.cpp b/dom/media/eme/MediaKeySystemAccess.cpp
new file mode 100644
index 000000000..7007d3a03
--- /dev/null
+++ b/dom/media/eme/MediaKeySystemAccess.cpp
@@ -0,0 +1,1135 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/MediaKeySystemAccess.h"
+#include "mozilla/dom/MediaKeySystemAccessBinding.h"
+#include "mozilla/Preferences.h"
+#include "MediaPrefs.h"
+#include "nsContentTypeParser.h"
+#ifdef MOZ_FMP4
+#include "MP4Decoder.h"
+#endif
+#ifdef XP_WIN
+#include "mozilla/WindowsVersion.h"
+#include "WMFDecoderModule.h"
+#endif
+#include "nsContentCID.h"
+#include "nsServiceManagerUtils.h"
+#include "mozIGeckoMediaPluginService.h"
+#include "VideoUtils.h"
+#include "mozilla/Services.h"
+#include "nsIObserverService.h"
+#include "mozilla/EMEUtils.h"
+#include "GMPUtils.h"
+#include "nsAppDirectoryServiceDefs.h"
+#include "nsDirectoryServiceUtils.h"
+#include "nsDirectoryServiceDefs.h"
+#include "nsXULAppAPI.h"
+#include "gmp-audio-decode.h"
+#include "gmp-video-decode.h"
+#include "DecoderDoctorDiagnostics.h"
+#include "WebMDecoder.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "nsUnicharUtils.h"
+#include "mozilla/dom/MediaSource.h"
+#ifdef MOZ_WIDGET_ANDROID
+#include "FennecJNIWrappers.h"
+#endif
+namespace mozilla {
+namespace dom {
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(MediaKeySystemAccess,
+                                      mParent)
+NS_IMPL_CYCLE_COLLECTING_ADDREF(MediaKeySystemAccess)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(MediaKeySystemAccess)
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(MediaKeySystemAccess)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+MediaKeySystemAccess::MediaKeySystemAccess(nsPIDOMWindowInner* aParent,
+                                           const nsAString& aKeySystem,
+                                           const MediaKeySystemConfiguration& aConfig)
+  : mParent(aParent)
+  , mKeySystem(aKeySystem)
+  , mConfig(aConfig)
+{
+}
+
+MediaKeySystemAccess::~MediaKeySystemAccess()
+{
+}
+
+JSObject*
+MediaKeySystemAccess::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
+{
+  return MediaKeySystemAccessBinding::Wrap(aCx, this, aGivenProto);
+}
+
+nsPIDOMWindowInner*
+MediaKeySystemAccess::GetParentObject() const
+{
+  return mParent;
+}
+
+void
+MediaKeySystemAccess::GetKeySystem(nsString& aOutKeySystem) const
+{
+  aOutKeySystem.Assign(mKeySystem);
+}
+
+void
+MediaKeySystemAccess::GetConfiguration(MediaKeySystemConfiguration& aConfig)
+{
+  aConfig = mConfig;
+}
+
+already_AddRefed<Promise>
+MediaKeySystemAccess::CreateMediaKeys(ErrorResult& aRv)
+{
+  RefPtr<MediaKeys> keys(new MediaKeys(mParent,
+                                       mKeySystem,
+                                       mConfig));
+  return keys->Init(aRv);
+}
+
+static bool
+HavePluginForKeySystem(const nsCString& aKeySystem)
+{
+  bool havePlugin = HaveGMPFor(NS_LITERAL_CSTRING(GMP_API_DECRYPTOR),
+                               { aKeySystem });
+#ifdef MOZ_WIDGET_ANDROID
+  // Check if we can use MediaDrm for this keysystem.
+  if (!havePlugin) {
+    havePlugin = mozilla::java::MediaDrmProxy::IsSchemeSupported(aKeySystem);
+  }
+#endif
+  return havePlugin;
+}
+
+static MediaKeySystemStatus
+EnsureCDMInstalled(const nsAString& aKeySystem,
+                    nsACString& aOutMessage)
+{
+  if (!HavePluginForKeySystem(NS_ConvertUTF16toUTF8(aKeySystem))) {
+    aOutMessage = NS_LITERAL_CSTRING("CDM is not installed");
+    return MediaKeySystemStatus::Cdm_not_installed;
+  }
+
+  return MediaKeySystemStatus::Available;
+}
+
+/* static */
+MediaKeySystemStatus
+MediaKeySystemAccess::GetKeySystemStatus(const nsAString& aKeySystem,
+                                         nsACString& aOutMessage)
+{
+  MOZ_ASSERT(MediaPrefs::EMEEnabled() || IsClearkeyKeySystem(aKeySystem));
+
+  if (IsClearkeyKeySystem(aKeySystem)) {
+    return EnsureCDMInstalled(aKeySystem, aOutMessage);
+  }
+
+  if (Preferences::GetBool("media.gmp-eme-adobe.visible", false)) {
+    if (IsPrimetimeKeySystem(aKeySystem)) {
+      if (!Preferences::GetBool("media.gmp-eme-adobe.enabled", false)) {
+        aOutMessage = NS_LITERAL_CSTRING("Adobe EME disabled");
+        return MediaKeySystemStatus::Cdm_disabled;
+      }
+#ifdef XP_WIN
+      // Win Vista and later only.
+      if (!IsVistaOrLater()) {
+        aOutMessage = NS_LITERAL_CSTRING("Minimum Windows version (Vista) not met for Adobe EME");
+        return MediaKeySystemStatus::Cdm_not_supported;
+      }
+#endif
+      return EnsureCDMInstalled(aKeySystem, aOutMessage);
+    }
+  }
+
+  if (IsWidevineKeySystem(aKeySystem)) {
+    if (Preferences::GetBool("media.gmp-widevinecdm.visible", false)) {
+#ifdef XP_WIN
+      // Win Vista and later only.
+      if (!IsVistaOrLater()) {
+        aOutMessage = NS_LITERAL_CSTRING("Minimum Windows version (Vista) not met for Widevine EME");
+        return MediaKeySystemStatus::Cdm_not_supported;
+      }
+#endif
+      if (!Preferences::GetBool("media.gmp-widevinecdm.enabled", false)) {
+        aOutMessage = NS_LITERAL_CSTRING("Widevine EME disabled");
+        return MediaKeySystemStatus::Cdm_disabled;
+      }
+      return EnsureCDMInstalled(aKeySystem, aOutMessage);
+#ifdef MOZ_WIDGET_ANDROID
+    } else if (Preferences::GetBool("media.mediadrm-widevinecdm.visible", false)) {
+        nsCString keySystem = NS_ConvertUTF16toUTF8(aKeySystem);
+        bool supported = mozilla::java::MediaDrmProxy::IsSchemeSupported(keySystem);
+        if (!supported) {
+          aOutMessage = NS_LITERAL_CSTRING("Widevine CDM is not available");
+          return MediaKeySystemStatus::Cdm_not_installed;
+        }
+        return MediaKeySystemStatus::Available;
+#endif
+    }
+  }
+
+  return MediaKeySystemStatus::Cdm_not_supported;
+}
+
+typedef nsCString EMECodecString;
+
+static NS_NAMED_LITERAL_CSTRING(EME_CODEC_AAC, "aac");
+static NS_NAMED_LITERAL_CSTRING(EME_CODEC_OPUS, "opus");
+static NS_NAMED_LITERAL_CSTRING(EME_CODEC_VORBIS, "vorbis");
+static NS_NAMED_LITERAL_CSTRING(EME_CODEC_H264, "h264");
+static NS_NAMED_LITERAL_CSTRING(EME_CODEC_VP8, "vp8");
+static NS_NAMED_LITERAL_CSTRING(EME_CODEC_VP9, "vp9");
+
+EMECodecString
+ToEMEAPICodecString(const nsString& aCodec)
+{
+  if (IsAACCodecString(aCodec)) {
+    return EME_CODEC_AAC;
+  }
+  if (aCodec.EqualsLiteral("opus")) {
+    return EME_CODEC_OPUS;
+  }
+  if (aCodec.EqualsLiteral("vorbis")) {
+    return EME_CODEC_VORBIS;
+  }
+  if (IsH264CodecString(aCodec)) {
+    return EME_CODEC_H264;
+  }
+  if (IsVP8CodecString(aCodec)) {
+    return EME_CODEC_VP8;
+  }
+  if (IsVP9CodecString(aCodec)) {
+    return EME_CODEC_VP9;
+  }
+  return EmptyCString();
+}
+
+// A codec can be decrypted-and-decoded by the CDM, or only decrypted
+// by the CDM and decoded by Gecko. Not both.
+struct KeySystemContainerSupport
+{
+  bool IsSupported() const
+  {
+    return !mCodecsDecoded.IsEmpty() || !mCodecsDecrypted.IsEmpty();
+  }
+
+  // CDM decrypts and decodes using a DRM robust decoder, and passes decoded
+  // samples back to Gecko for rendering.
+  bool DecryptsAndDecodes(EMECodecString aCodec) const
+  {
+    return mCodecsDecoded.Contains(aCodec);
+  }
+
+  // CDM decrypts and passes the decrypted samples back to Gecko for decoding.
+  bool Decrypts(EMECodecString aCodec) const
+  {
+    return mCodecsDecrypted.Contains(aCodec);
+  }
+
+  void SetCanDecryptAndDecode(EMECodecString aCodec)
+  {
+    // Can't both decrypt and decrypt-and-decode a codec.
+    MOZ_ASSERT(!Decrypts(aCodec));
+    // Prevent duplicates.
+    MOZ_ASSERT(!DecryptsAndDecodes(aCodec));
+    mCodecsDecoded.AppendElement(aCodec);
+  }
+
+  void SetCanDecrypt(EMECodecString aCodec)
+  {
+    // Prevent duplicates.
+    MOZ_ASSERT(!Decrypts(aCodec));
+    // Can't both decrypt and decrypt-and-decode a codec.
+    MOZ_ASSERT(!DecryptsAndDecodes(aCodec));
+    mCodecsDecrypted.AppendElement(aCodec);
+  }
+
+private:
+  nsTArray<EMECodecString> mCodecsDecoded;
+  nsTArray<EMECodecString> mCodecsDecrypted;
+};
+
+enum class KeySystemFeatureSupport
+{
+  Prohibited = 1,
+  Requestable = 2,
+  Required = 3,
+};
+
+struct KeySystemConfig
+{
+  nsString mKeySystem;
+  nsTArray<nsString> mInitDataTypes;
+  KeySystemFeatureSupport mPersistentState = KeySystemFeatureSupport::Prohibited;
+  KeySystemFeatureSupport mDistinctiveIdentifier = KeySystemFeatureSupport::Prohibited;
+  nsTArray<MediaKeySessionType> mSessionTypes;
+  nsTArray<nsString> mVideoRobustness;
+  nsTArray<nsString> mAudioRobustness;
+  KeySystemContainerSupport mMP4;
+  KeySystemContainerSupport mWebM;
+};
+
+static nsTArray<KeySystemConfig>
+GetSupportedKeySystems()
+{
+  nsTArray<KeySystemConfig> keySystemConfigs;
+
+  {
+    if (HavePluginForKeySystem(kEMEKeySystemClearkey)) {
+      KeySystemConfig clearkey;
+      clearkey.mKeySystem = NS_ConvertUTF8toUTF16(kEMEKeySystemClearkey);
+      clearkey.mInitDataTypes.AppendElement(NS_LITERAL_STRING("cenc"));
+      clearkey.mInitDataTypes.AppendElement(NS_LITERAL_STRING("keyids"));
+      clearkey.mInitDataTypes.AppendElement(NS_LITERAL_STRING("webm"));
+      clearkey.mPersistentState = KeySystemFeatureSupport::Requestable;
+      clearkey.mDistinctiveIdentifier = KeySystemFeatureSupport::Prohibited;
+      clearkey.mSessionTypes.AppendElement(MediaKeySessionType::Temporary);
+      if (MediaPrefs::ClearKeyPersistentLicenseEnabled()) {
+        clearkey.mSessionTypes.AppendElement(MediaKeySessionType::Persistent_license);
+      }
+#if defined(XP_WIN)
+      // Clearkey CDM uses WMF decoders on Windows.
+      if (WMFDecoderModule::HasAAC()) {
+        clearkey.mMP4.SetCanDecryptAndDecode(EME_CODEC_AAC);
+      } else {
+        clearkey.mMP4.SetCanDecrypt(EME_CODEC_AAC);
+      }
+      if (WMFDecoderModule::HasH264()) {
+        clearkey.mMP4.SetCanDecryptAndDecode(EME_CODEC_H264);
+      } else {
+        clearkey.mMP4.SetCanDecrypt(EME_CODEC_H264);
+      }
+#else
+      clearkey.mMP4.SetCanDecrypt(EME_CODEC_AAC);
+      clearkey.mMP4.SetCanDecrypt(EME_CODEC_H264);
+#endif
+      clearkey.mWebM.SetCanDecrypt(EME_CODEC_VORBIS);
+      clearkey.mWebM.SetCanDecrypt(EME_CODEC_OPUS);
+      clearkey.mWebM.SetCanDecrypt(EME_CODEC_VP8);
+      clearkey.mWebM.SetCanDecrypt(EME_CODEC_VP9);
+      keySystemConfigs.AppendElement(Move(clearkey));
+    }
+  }
+  {
+    if (HavePluginForKeySystem(kEMEKeySystemWidevine)) {
+      KeySystemConfig widevine;
+      widevine.mKeySystem = NS_ConvertUTF8toUTF16(kEMEKeySystemWidevine);
+      widevine.mInitDataTypes.AppendElement(NS_LITERAL_STRING("cenc"));
+      widevine.mInitDataTypes.AppendElement(NS_LITERAL_STRING("keyids"));
+      widevine.mInitDataTypes.AppendElement(NS_LITERAL_STRING("webm"));
+      widevine.mPersistentState = KeySystemFeatureSupport::Requestable;
+      widevine.mDistinctiveIdentifier = KeySystemFeatureSupport::Prohibited;
+      widevine.mSessionTypes.AppendElement(MediaKeySessionType::Temporary);
+#ifdef MOZ_WIDGET_ANDROID
+      widevine.mSessionTypes.AppendElement(MediaKeySessionType::Persistent_license);
+#endif
+      widevine.mAudioRobustness.AppendElement(NS_LITERAL_STRING("SW_SECURE_CRYPTO"));
+      widevine.mVideoRobustness.AppendElement(NS_LITERAL_STRING("SW_SECURE_DECODE"));
+#if defined(XP_WIN)
+      // Widevine CDM doesn't include an AAC decoder. So if WMF can't
+      // decode AAC, and a codec wasn't specified, be conservative
+      // and reject the MediaKeys request, since our policy is to prevent
+      //  the Adobe GMP's unencrypted AAC decoding path being used to
+      // decode content decrypted by the Widevine CDM.
+      if (WMFDecoderModule::HasAAC()) {
+        widevine.mMP4.SetCanDecrypt(EME_CODEC_AAC);
+      }
+#elif !defined(MOZ_WIDGET_ANDROID)
+      widevine.mMP4.SetCanDecrypt(EME_CODEC_AAC);
+#endif
+
+#if defined(MOZ_WIDGET_ANDROID)
+      using namespace mozilla::java;
+      // MediaDrm.isCryptoSchemeSupported only allows passing
+      // "video/mp4" or "video/webm" for mimetype string.
+      // See https://developer.android.com/reference/android/media/MediaDrm.html#isCryptoSchemeSupported(java.util.UUID, java.lang.String)
+      // for more detail.
+      typedef struct {
+        const nsCString& mMimeType;
+        const nsCString& mEMECodecType;
+        const char16_t* mCodecType;
+        KeySystemContainerSupport* mSupportType;
+      } DataForValidation;
+
+      DataForValidation validationList[] = {
+        { nsCString("video/mp4"), EME_CODEC_H264, MediaDrmProxy::AVC, &widevine.mMP4 },
+        { nsCString("audio/mp4"), EME_CODEC_AAC, MediaDrmProxy::AAC, &widevine.mMP4 },
+        { nsCString("video/webm"), EME_CODEC_VP8, MediaDrmProxy::VP8, &widevine.mWebM },
+        { nsCString("video/webm"), EME_CODEC_VP9, MediaDrmProxy::VP9, &widevine.mWebM},
+        { nsCString("audio/webm"), EME_CODEC_VORBIS, MediaDrmProxy::VORBIS, &widevine.mWebM},
+        { nsCString("audio/webm"), EME_CODEC_OPUS, MediaDrmProxy::OPUS, &widevine.mWebM},
+      };
+
+      for (const auto& data: validationList) {
+        if (MediaDrmProxy::IsCryptoSchemeSupported(kEMEKeySystemWidevine,
+                                                   data.mMimeType)) {
+          if (MediaDrmProxy::CanDecode(data.mCodecType)) {
+            data.mSupportType->SetCanDecryptAndDecode(data.mEMECodecType);
+          } else {
+            data.mSupportType->SetCanDecrypt(data.mEMECodecType);
+          }
+        }
+      }
+#else
+      widevine.mMP4.SetCanDecryptAndDecode(EME_CODEC_H264);
+      widevine.mWebM.SetCanDecrypt(EME_CODEC_VORBIS);
+      widevine.mWebM.SetCanDecrypt(EME_CODEC_OPUS);
+      widevine.mWebM.SetCanDecryptAndDecode(EME_CODEC_VP8);
+      widevine.mWebM.SetCanDecryptAndDecode(EME_CODEC_VP9);
+#endif
+      keySystemConfigs.AppendElement(Move(widevine));
+    }
+  }
+  {
+    if (HavePluginForKeySystem(kEMEKeySystemPrimetime)) {
+      KeySystemConfig primetime;
+      primetime.mKeySystem = NS_ConvertUTF8toUTF16(kEMEKeySystemPrimetime);
+      primetime.mInitDataTypes.AppendElement(NS_LITERAL_STRING("cenc"));
+      primetime.mPersistentState = KeySystemFeatureSupport::Required;
+      primetime.mDistinctiveIdentifier = KeySystemFeatureSupport::Required;
+      primetime.mSessionTypes.AppendElement(MediaKeySessionType::Temporary);
+      primetime.mMP4.SetCanDecryptAndDecode(EME_CODEC_AAC);
+      primetime.mMP4.SetCanDecryptAndDecode(EME_CODEC_H264);
+      keySystemConfigs.AppendElement(Move(primetime));
+    }
+  }
+
+  return keySystemConfigs;
+}
+
+static bool
+GetKeySystemConfig(const nsAString& aKeySystem, KeySystemConfig& aOutKeySystemConfig)
+{
+  for (auto&& config : GetSupportedKeySystems()) {
+    if (config.mKeySystem.Equals(aKeySystem)) {
+      aOutKeySystemConfig = mozilla::Move(config);
+      return true;
+    }
+  }
+  // No matching key system found.
+  return false;
+}
+
+/* static */
+bool
+MediaKeySystemAccess::KeySystemSupportsInitDataType(const nsAString& aKeySystem,
+                                                    const nsAString& aInitDataType)
+{
+  KeySystemConfig implementation;
+  return GetKeySystemConfig(aKeySystem, implementation) &&
+         implementation.mInitDataTypes.Contains(aInitDataType);
+}
+
+enum CodecType
+{
+  Audio,
+  Video,
+  Invalid
+};
+
+static bool
+CanDecryptAndDecode(const nsString& aKeySystem,
+                    const nsString& aContentType,
+                    CodecType aCodecType,
+                    const KeySystemContainerSupport& aContainerSupport,
+                    const nsTArray<EMECodecString>& aCodecs,
+                    DecoderDoctorDiagnostics* aDiagnostics)
+{
+  MOZ_ASSERT(aCodecType != Invalid);
+  for (const EMECodecString& codec : aCodecs) {
+    MOZ_ASSERT(!codec.IsEmpty());
+
+    if (aContainerSupport.DecryptsAndDecodes(codec)) {
+      // GMP can decrypt-and-decode this codec.
+      continue;
+    }
+
+    if (aContainerSupport.Decrypts(codec) &&
+        NS_SUCCEEDED(MediaSource::IsTypeSupported(aContentType, aDiagnostics))) {
+      // GMP can decrypt and is allowed to return compressed samples to
+      // Gecko to decode, and Gecko has a decoder.
+      continue;
+    }
+
+    // Neither the GMP nor Gecko can both decrypt and decode. We don't
+    // support this codec.
+
+#if defined(XP_WIN)
+    // Widevine CDM doesn't include an AAC decoder. So if WMF can't
+    // decode AAC, and a codec wasn't specified, be conservative
+    // and reject the MediaKeys request, since our policy is to prevent
+    //  the Adobe GMP's unencrypted AAC decoding path being used to
+    // decode content decrypted by the Widevine CDM.
+    if (codec == EME_CODEC_AAC &&
+        IsWidevineKeySystem(aKeySystem) &&
+        !WMFDecoderModule::HasAAC()) {
+      if (aDiagnostics) {
+        aDiagnostics->SetKeySystemIssue(
+          DecoderDoctorDiagnostics::eWidevineWithNoWMF);
+      }
+    }
+#endif
+    return false;
+  }
+  return true;
+}
+
+static bool
+ToSessionType(const nsAString& aSessionType, MediaKeySessionType& aOutType)
+{
+  using MediaKeySessionTypeValues::strings;
+  const char* temporary =
+    strings[static_cast<uint32_t>(MediaKeySessionType::Temporary)].value;
+  if (aSessionType.EqualsASCII(temporary)) {
+    aOutType = MediaKeySessionType::Temporary;
+    return true;
+  }
+  const char* persistentLicense =
+    strings[static_cast<uint32_t>(MediaKeySessionType::Persistent_license)].value;
+  if (aSessionType.EqualsASCII(persistentLicense)) {
+    aOutType = MediaKeySessionType::Persistent_license;
+    return true;
+  }
+  return false;
+}
+
+// 5.2.1 Is persistent session type?
+static bool
+IsPersistentSessionType(MediaKeySessionType aSessionType)
+{
+  return aSessionType == MediaKeySessionType::Persistent_license;
+}
+
+CodecType
+GetMajorType(const nsAString& aContentType)
+{
+  if (CaseInsensitiveFindInReadable(NS_LITERAL_STRING("audio/"), aContentType)) {
+    return Audio;
+  }
+  if (CaseInsensitiveFindInReadable(NS_LITERAL_STRING("video/"), aContentType)) {
+    return Video;
+  }
+  return Invalid;
+}
+
+static CodecType
+GetCodecType(const EMECodecString& aCodec)
+{
+  if (aCodec.Equals(EME_CODEC_AAC) ||
+      aCodec.Equals(EME_CODEC_OPUS) ||
+      aCodec.Equals(EME_CODEC_VORBIS)) {
+    return Audio;
+  }
+  if (aCodec.Equals(EME_CODEC_H264) ||
+      aCodec.Equals(EME_CODEC_VP8) ||
+      aCodec.Equals(EME_CODEC_VP9)) {
+    return Video;
+  }
+  return Invalid;
+}
+
+static bool
+AllCodecsOfType(const nsTArray<EMECodecString>& aCodecs, const CodecType aCodecType)
+{
+  for (const EMECodecString& codec : aCodecs) {
+    if (GetCodecType(codec) != aCodecType) {
+      return false;
+    }
+  }
+  return true;
+}
+
+static bool
+IsParameterUnrecognized(const nsAString& aContentType)
+{
+  nsAutoString contentType(aContentType);
+  contentType.StripWhitespace();
+
+  nsTArray<nsString> params;
+  nsAString::const_iterator start, end, semicolon, equalSign;
+  contentType.BeginReading(start);
+  contentType.EndReading(end);
+  semicolon = start;
+  // Find any substring between ';' & '='.
+  while (semicolon != end) {
+    if (FindCharInReadable(';', semicolon, end)) {
+      equalSign = ++semicolon;
+      if (FindCharInReadable('=', equalSign, end)) {
+        params.AppendElement(Substring(semicolon, equalSign));
+        semicolon = equalSign;
+      }
+    }
+  }
+
+  for (auto param : params) {
+    if (!param.LowerCaseEqualsLiteral("codecs") &&
+        !param.LowerCaseEqualsLiteral("profiles")) {
+      return true;
+    }
+  }
+  return false;
+}
+
+// 3.1.2.3 Get Supported Capabilities for Audio/Video Type
+static Sequence<MediaKeySystemMediaCapability>
+GetSupportedCapabilities(const CodecType aCodecType,
+                         const nsTArray<MediaKeySystemMediaCapability>& aRequestedCapabilities,
+                         const MediaKeySystemConfiguration& aPartialConfig,
+                         const KeySystemConfig& aKeySystem,
+                         DecoderDoctorDiagnostics* aDiagnostics)
+{
+  // Let local accumulated configuration be a local copy of partial configuration.
+  // (Note: It's not necessary for us to maintain a local copy, as we don't need
+  // to test whether capabilites from previous calls to this algorithm work with
+  // the capabilities currently being considered in this call. )
+
+  // Let supported media capabilities be an empty sequence of
+  // MediaKeySystemMediaCapability dictionaries.
+  Sequence<MediaKeySystemMediaCapability> supportedCapabilities;
+
+  // For each requested media capability in requested media capabilities:
+  for (const MediaKeySystemMediaCapability& capabilities : aRequestedCapabilities) {
+    // Let content type be requested media capability's contentType member.
+    const nsString& contentType = capabilities.mContentType;
+    // Let robustness be requested media capability's robustness member.
+    const nsString& robustness = capabilities.mRobustness;
+    // If content type is the empty string, return null.
+    if (contentType.IsEmpty()) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') "
+              "MediaKeySystemMediaCapability('%s','%s') rejected; "
+              "audio or video capability has empty contentType.",
+              NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+              NS_ConvertUTF16toUTF8(contentType).get(),
+              NS_ConvertUTF16toUTF8(robustness).get());
+      return Sequence<MediaKeySystemMediaCapability>();
+    }
+    // If content type is an invalid or unrecognized MIME type, continue
+    // to the next iteration.
+    nsAutoString container;
+    nsTArray<nsString> codecStrings;
+    if (!ParseMIMETypeString(contentType, container, codecStrings)) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') "
+              "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+              "failed to parse contentType as MIME type.",
+              NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+              NS_ConvertUTF16toUTF8(contentType).get(),
+              NS_ConvertUTF16toUTF8(robustness).get());
+      continue;
+    }
+    bool invalid = false;
+    nsTArray<EMECodecString> codecs;
+    for (const nsString& codecString : codecStrings) {
+      EMECodecString emeCodec = ToEMEAPICodecString(codecString);
+      if (emeCodec.IsEmpty()) {
+        invalid = true;
+        EME_LOG("MediaKeySystemConfiguration (label='%s') "
+                "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+                "'%s' is an invalid codec string.",
+                NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+                NS_ConvertUTF16toUTF8(contentType).get(),
+                NS_ConvertUTF16toUTF8(robustness).get(),
+                NS_ConvertUTF16toUTF8(codecString).get());
+        break;
+      }
+      codecs.AppendElement(emeCodec);
+    }
+    if (invalid) {
+      continue;
+    }
+
+    // If the user agent does not support container, continue to the next iteration.
+    // The case-sensitivity of string comparisons is determined by the appropriate RFC.
+    // (Note: Per RFC 6838 [RFC6838], "Both top-level type and subtype names are
+    // case-insensitive."'. We're using nsContentTypeParser and that is
+    // case-insensitive and converts all its parameter outputs to lower case.)
+    NS_ConvertUTF16toUTF8 container_utf8(container);
+    const bool isMP4 = DecoderTraits::IsMP4TypeAndEnabled(container_utf8, aDiagnostics);
+    if (isMP4 && !aKeySystem.mMP4.IsSupported()) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') "
+              "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+              "MP4 requested but unsupported.",
+              NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+              NS_ConvertUTF16toUTF8(contentType).get(),
+              NS_ConvertUTF16toUTF8(robustness).get());
+      continue;
+    }
+    const bool isWebM = DecoderTraits::IsWebMTypeAndEnabled(container_utf8);
+    if (isWebM && !aKeySystem.mWebM.IsSupported()) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') "
+              "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+              "WebM requested but unsupported.",
+              NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+              NS_ConvertUTF16toUTF8(contentType).get(),
+              NS_ConvertUTF16toUTF8(robustness).get());
+      continue;
+    }
+    if (!isMP4 && !isWebM) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') "
+              "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+              "Unsupported or unrecognized container requested.",
+              NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+              NS_ConvertUTF16toUTF8(contentType).get(),
+              NS_ConvertUTF16toUTF8(robustness).get());
+      continue;
+    }
+
+    // Let parameters be the RFC 6381[RFC6381] parameters, if any, specified by
+    // content type.
+    // If the user agent does not recognize one or more parameters, continue to
+    // the next iteration.
+    if (IsParameterUnrecognized(contentType)) {
+      continue;
+    }
+
+    // Let media types be the set of codecs and codec constraints specified by
+    // parameters. The case-sensitivity of string comparisons is determined by
+    // the appropriate RFC or other specification.
+    // (Note: codecs array is 'parameter').
+
+    // If media types is empty:
+    if (codecs.IsEmpty()) {
+      // If container normatively implies a specific set of codecs and codec constraints:
+      // Let parameters be that set.
+      if (isMP4) {
+        if (aCodecType == Audio) {
+          codecs.AppendElement(EME_CODEC_AAC);
+        } else if (aCodecType == Video) {
+          codecs.AppendElement(EME_CODEC_H264);
+        }
+      } else if (isWebM) {
+        if (aCodecType == Audio) {
+          codecs.AppendElement(EME_CODEC_VORBIS);
+        } else if (aCodecType == Video) {
+          codecs.AppendElement(EME_CODEC_VP8);
+        }
+      }
+      // Otherwise: Continue to the next iteration.
+      // (Note: all containers we support have implied codecs, so don't continue here.)
+    }
+
+    // If content type is not strictly a audio/video type, continue to the next iteration.
+    const auto majorType = GetMajorType(container);
+    if (majorType == Invalid) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') "
+              "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+              "MIME type is not an audio or video MIME type.",
+              NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+              NS_ConvertUTF16toUTF8(contentType).get(),
+              NS_ConvertUTF16toUTF8(robustness).get());
+      continue;
+    }
+    if (majorType != aCodecType || !AllCodecsOfType(codecs, aCodecType)) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') "
+              "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+              "MIME type mixes audio codecs in video capabilities "
+              "or video codecs in audio capabilities.",
+              NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+              NS_ConvertUTF16toUTF8(contentType).get(),
+              NS_ConvertUTF16toUTF8(robustness).get());
+      continue;
+    }
+    // If robustness is not the empty string and contains an unrecognized
+    // value or a value not supported by implementation, continue to the
+    // next iteration. String comparison is case-sensitive.
+    if (!robustness.IsEmpty()) {
+      if (majorType == Audio && !aKeySystem.mAudioRobustness.Contains(robustness)) {
+        EME_LOG("MediaKeySystemConfiguration (label='%s') "
+                "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+                "unsupported robustness string.",
+                NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+                NS_ConvertUTF16toUTF8(contentType).get(),
+                NS_ConvertUTF16toUTF8(robustness).get());
+        continue;
+      }
+      if (majorType == Video && !aKeySystem.mVideoRobustness.Contains(robustness)) {
+        EME_LOG("MediaKeySystemConfiguration (label='%s') "
+                "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+                "unsupported robustness string.",
+                NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+                NS_ConvertUTF16toUTF8(contentType).get(),
+                NS_ConvertUTF16toUTF8(robustness).get());
+        continue;
+      }
+      // Note: specified robustness requirements are satisfied.
+    }
+
+    // If the user agent and implementation definitely support playback of
+    // encrypted media data for the combination of container, media types,
+    // robustness and local accumulated configuration in combination with
+    // restrictions...
+    const auto& containerSupport = isMP4 ? aKeySystem.mMP4 : aKeySystem.mWebM;
+    if (!CanDecryptAndDecode(aKeySystem.mKeySystem,
+                             contentType,
+                             majorType,
+                             containerSupport,
+                             codecs,
+                             aDiagnostics)) {
+        EME_LOG("MediaKeySystemConfiguration (label='%s') "
+                "MediaKeySystemMediaCapability('%s','%s') unsupported; "
+                "codec unsupported by CDM requested.",
+                NS_ConvertUTF16toUTF8(aPartialConfig.mLabel).get(),
+                NS_ConvertUTF16toUTF8(contentType).get(),
+                NS_ConvertUTF16toUTF8(robustness).get());
+        continue;
+    }
+
+    // ... add requested media capability to supported media capabilities.
+    if (!supportedCapabilities.AppendElement(capabilities, mozilla::fallible)) {
+      NS_WARNING("GetSupportedCapabilities: Malloc failure");
+      return Sequence<MediaKeySystemMediaCapability>();
+    }
+
+    // Note: omitting steps 3.13.2, our robustness is not sophisticated enough
+    // to require considering all requirements together.
+  }
+  return Move(supportedCapabilities);
+}
+
+// "Get Supported Configuration and Consent" algorithm, steps 4-7 for
+// distinctive identifier, and steps 8-11 for persistent state. The steps
+// are the same for both requirements/features, so we factor them out into
+// a single function.
+static bool
+CheckRequirement(const MediaKeysRequirement aRequirement,
+                 const KeySystemFeatureSupport aFeatureSupport,
+                 MediaKeysRequirement& aOutRequirement)
+{
+  // Let requirement be the value of candidate configuration's member.
+  MediaKeysRequirement requirement = aRequirement;
+  // If requirement is "optional" and feature is not allowed according to
+  // restrictions, set requirement to "not-allowed".
+  if (aRequirement == MediaKeysRequirement::Optional &&
+      aFeatureSupport == KeySystemFeatureSupport::Prohibited) {
+    requirement = MediaKeysRequirement::Not_allowed;
+  }
+
+  // Follow the steps for requirement from the following list:
+  switch (requirement) {
+    case MediaKeysRequirement::Required: {
+      // If the implementation does not support use of requirement in combination
+      // with accumulated configuration and restrictions, return NotSupported.
+      if (aFeatureSupport == KeySystemFeatureSupport::Prohibited) {
+        return false;
+      }
+      break;
+    }
+    case MediaKeysRequirement::Optional: {
+      // Continue with the following steps.
+      break;
+    }
+    case MediaKeysRequirement::Not_allowed: {
+      // If the implementation requires use of feature in combination with
+      // accumulated configuration and restrictions, return NotSupported.
+      if (aFeatureSupport == KeySystemFeatureSupport::Required) {
+        return false;
+      }
+      break;
+    }
+    default: {
+      return false;
+    }
+  }
+
+  // Set the requirement member of accumulated configuration to equal
+  // calculated requirement.
+  aOutRequirement = requirement;
+
+  return true;
+}
+
+// 3.1.2.2, step 12
+// Follow the steps for the first matching condition from the following list:
+// If the sessionTypes member is present in candidate configuration.
+// Let session types be candidate configuration's sessionTypes member.
+// Otherwise let session types be ["temporary"].
+// Note: This returns an empty array on malloc failure.
+static Sequence<nsString>
+UnboxSessionTypes(const Optional<Sequence<nsString>>& aSessionTypes)
+{
+  Sequence<nsString> sessionTypes;
+  if (aSessionTypes.WasPassed()) {
+    sessionTypes = aSessionTypes.Value();
+  } else {
+    using MediaKeySessionTypeValues::strings;
+    const char* temporary = strings[static_cast<uint32_t>(MediaKeySessionType::Temporary)].value;
+    // Note: fallible. Results in an empty array.
+    sessionTypes.AppendElement(NS_ConvertUTF8toUTF16(nsDependentCString(temporary)), mozilla::fallible);
+  }
+  return sessionTypes;
+}
+
+// 3.1.2.2 Get Supported Configuration and Consent
+static bool
+GetSupportedConfig(const KeySystemConfig& aKeySystem,
+                   const MediaKeySystemConfiguration& aCandidate,
+                   MediaKeySystemConfiguration& aOutConfig,
+                   DecoderDoctorDiagnostics* aDiagnostics)
+{
+  // Let accumulated configuration be a new MediaKeySystemConfiguration dictionary.
+  MediaKeySystemConfiguration config;
+  // Set the label member of accumulated configuration to equal the label member of
+  // candidate configuration.
+  config.mLabel = aCandidate.mLabel;
+  // If the initDataTypes member of candidate configuration is non-empty, run the
+  // following steps:
+  if (!aCandidate.mInitDataTypes.IsEmpty()) {
+    // Let supported types be an empty sequence of DOMStrings.
+    nsTArray<nsString> supportedTypes;
+    // For each value in candidate configuration's initDataTypes member:
+    for (const nsString& initDataType : aCandidate.mInitDataTypes) {
+      // Let initDataType be the value.
+      // If the implementation supports generating requests based on initDataType,
+      // add initDataType to supported types. String comparison is case-sensitive.
+      // The empty string is never supported.
+      if (aKeySystem.mInitDataTypes.Contains(initDataType)) {
+        supportedTypes.AppendElement(initDataType);
+      }
+    }
+    // If supported types is empty, return NotSupported.
+    if (supportedTypes.IsEmpty()) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') rejected; "
+              "no supported initDataTypes provided.",
+              NS_ConvertUTF16toUTF8(aCandidate.mLabel).get());
+      return false;
+    }
+    // Set the initDataTypes member of accumulated configuration to supported types.
+    if (!config.mInitDataTypes.Assign(supportedTypes)) {
+      return false;
+    }
+  }
+
+  if (!CheckRequirement(aCandidate.mDistinctiveIdentifier,
+                        aKeySystem.mDistinctiveIdentifier,
+                        config.mDistinctiveIdentifier)) {
+    EME_LOG("MediaKeySystemConfiguration (label='%s') rejected; "
+            "distinctiveIdentifier requirement not satisfied.",
+            NS_ConvertUTF16toUTF8(aCandidate.mLabel).get());
+    return false;
+  }
+
+  if (!CheckRequirement(aCandidate.mPersistentState,
+                        aKeySystem.mPersistentState,
+                        config.mPersistentState)) {
+    EME_LOG("MediaKeySystemConfiguration (label='%s') rejected; "
+            "persistentState requirement not satisfied.",
+            NS_ConvertUTF16toUTF8(aCandidate.mLabel).get());
+    return false;
+  }
+
+  Sequence<nsString> sessionTypes(UnboxSessionTypes(aCandidate.mSessionTypes));
+  if (sessionTypes.IsEmpty()) {
+    // Malloc failure.
+    return false;
+  }
+
+  // For each value in session types:
+  for (const auto& sessionTypeString : sessionTypes) {
+    // Let session type be the value.
+    MediaKeySessionType sessionType;
+    if (!ToSessionType(sessionTypeString, sessionType)) {
+      // (Assume invalid sessionType is unsupported as per steps below).
+      EME_LOG("MediaKeySystemConfiguration (label='%s') rejected; "
+              "invalid session type specified.",
+              NS_ConvertUTF16toUTF8(aCandidate.mLabel).get());
+      return false;
+    }
+    // If accumulated configuration's persistentState value is "not-allowed"
+    // and the Is persistent session type? algorithm returns true for session
+    // type return NotSupported.
+    if (config.mPersistentState == MediaKeysRequirement::Not_allowed &&
+        IsPersistentSessionType(sessionType)) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') rejected; "
+              "persistent session requested but keysystem doesn't"
+              "support persistent state.",
+              NS_ConvertUTF16toUTF8(aCandidate.mLabel).get());
+      return false;
+    }
+    // If the implementation does not support session type in combination
+    // with accumulated configuration and restrictions for other reasons,
+    // return NotSupported.
+    if (!aKeySystem.mSessionTypes.Contains(sessionType)) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') rejected; "
+              "session type '%s' unsupported by keySystem.",
+              NS_ConvertUTF16toUTF8(aCandidate.mLabel).get(),
+              NS_ConvertUTF16toUTF8(sessionTypeString).get());
+      return false;
+    }
+    // If accumulated configuration's persistentState value is "optional"
+    // and the result of running the Is persistent session type? algorithm
+    // on session type is true, change accumulated configuration's
+    // persistentState value to "required".
+    if (config.mPersistentState == MediaKeysRequirement::Optional &&
+        IsPersistentSessionType(sessionType)) {
+      config.mPersistentState = MediaKeysRequirement::Required;
+    }
+  }
+  // Set the sessionTypes member of accumulated configuration to session types.
+  config.mSessionTypes.Construct(Move(sessionTypes));
+
+  // If the videoCapabilities and audioCapabilities members in candidate
+  // configuration are both empty, return NotSupported.
+  // TODO: Most sites using EME still don't pass capabilities, so we
+  // can't reject on it yet without breaking them. So add this later.
+
+  // If the videoCapabilities member in candidate configuration is non-empty:
+  if (!aCandidate.mVideoCapabilities.IsEmpty()) {
+    // Let video capabilities be the result of executing the Get Supported
+    // Capabilities for Audio/Video Type algorithm on Video, candidate
+    // configuration's videoCapabilities member, accumulated configuration,
+    // and restrictions.
+    Sequence<MediaKeySystemMediaCapability> caps =
+      GetSupportedCapabilities(Video,
+                               aCandidate.mVideoCapabilities,
+                               config,
+                               aKeySystem,
+                               aDiagnostics);
+    // If video capabilities is null, return NotSupported.
+    if (caps.IsEmpty()) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') rejected; "
+              "no supported video capabilities.",
+              NS_ConvertUTF16toUTF8(aCandidate.mLabel).get());
+      return false;
+    }
+    // Set the videoCapabilities member of accumulated configuration to video capabilities.
+    config.mVideoCapabilities = Move(caps);
+  } else {
+    // Otherwise:
+    // Set the videoCapabilities member of accumulated configuration to an empty sequence.
+  }
+
+  // If the audioCapabilities member in candidate configuration is non-empty:
+  if (!aCandidate.mAudioCapabilities.IsEmpty()) {
+    // Let audio capabilities be the result of executing the Get Supported Capabilities
+    // for Audio/Video Type algorithm on Audio, candidate configuration's audioCapabilities
+    // member, accumulated configuration, and restrictions.
+    Sequence<MediaKeySystemMediaCapability> caps =
+      GetSupportedCapabilities(Audio,
+                               aCandidate.mAudioCapabilities,
+                               config,
+                               aKeySystem,
+                               aDiagnostics);
+    // If audio capabilities is null, return NotSupported.
+    if (caps.IsEmpty()) {
+      EME_LOG("MediaKeySystemConfiguration (label='%s') rejected; "
+              "no supported audio capabilities.",
+              NS_ConvertUTF16toUTF8(aCandidate.mLabel).get());
+      return false;
+    }
+    // Set the audioCapabilities member of accumulated configuration to audio capabilities.
+    config.mAudioCapabilities = Move(caps);
+  } else {
+    // Otherwise:
+    // Set the audioCapabilities member of accumulated configuration to an empty sequence.
+  }
+
+  // If accumulated configuration's distinctiveIdentifier value is "optional", follow the
+  // steps for the first matching condition from the following list:
+  if (config.mDistinctiveIdentifier == MediaKeysRequirement::Optional) {
+    // If the implementation requires use Distinctive Identifier(s) or
+    // Distinctive Permanent Identifier(s) for any of the combinations
+    // in accumulated configuration
+    if (aKeySystem.mDistinctiveIdentifier == KeySystemFeatureSupport::Required) {
+      // Change accumulated configuration's distinctiveIdentifier value to "required".
+      config.mDistinctiveIdentifier = MediaKeysRequirement::Required;
+    } else {
+      // Otherwise, change accumulated configuration's distinctiveIdentifier
+      // value to "not-allowed".
+      config.mDistinctiveIdentifier = MediaKeysRequirement::Not_allowed;
+    }
+  }
+
+  // If accumulated configuration's persistentState value is "optional", follow the
+  // steps for the first matching condition from the following list:
+  if (config.mPersistentState == MediaKeysRequirement::Optional) {
+    // If the implementation requires persisting state for any of the combinations
+    // in accumulated configuration
+    if (aKeySystem.mPersistentState == KeySystemFeatureSupport::Required) {
+      // Change accumulated configuration's persistentState value to "required".
+      config.mPersistentState = MediaKeysRequirement::Required;
+    } else {
+      // Otherwise, change accumulated configuration's persistentState
+      // value to "not-allowed".
+      config.mPersistentState = MediaKeysRequirement::Not_allowed;
+    }
+  }
+
+  // Note: Omitting steps 20-22. We don't ask for consent.
+
+#if defined(XP_WIN)
+  // Widevine CDM doesn't include an AAC decoder. So if WMF can't decode AAC,
+  // and a codec wasn't specified, be conservative and reject the MediaKeys request.
+  if (IsWidevineKeySystem(aKeySystem.mKeySystem) &&
+      (aCandidate.mAudioCapabilities.IsEmpty() ||
+       aCandidate.mVideoCapabilities.IsEmpty()) &&
+     !WMFDecoderModule::HasAAC()) {
+    if (aDiagnostics) {
+      aDiagnostics->SetKeySystemIssue(
+        DecoderDoctorDiagnostics::eWidevineWithNoWMF);
+    }
+    EME_LOG("MediaKeySystemConfiguration (label='%s') rejected; "
+            "WMF required for Widevine decoding, but it's not available.",
+            NS_ConvertUTF16toUTF8(aCandidate.mLabel).get());
+    return false;
+  }
+#endif
+
+  // Return accumulated configuration.
+  aOutConfig = config;
+
+  return true;
+}
+
+/* static */
+bool
+MediaKeySystemAccess::GetSupportedConfig(const nsAString& aKeySystem,
+                                         const Sequence<MediaKeySystemConfiguration>& aConfigs,
+                                         MediaKeySystemConfiguration& aOutConfig,
+                                         DecoderDoctorDiagnostics* aDiagnostics)
+{
+  KeySystemConfig implementation;
+  if (!GetKeySystemConfig(aKeySystem, implementation)) {
+    return false;
+  }
+  for (const MediaKeySystemConfiguration& candidate : aConfigs) {
+    if (mozilla::dom::GetSupportedConfig(implementation,
+                                         candidate,
+                                         aOutConfig,
+                                         aDiagnostics)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+
+/* static */
+void
+MediaKeySystemAccess::NotifyObservers(nsPIDOMWindowInner* aWindow,
+                                      const nsAString& aKeySystem,
+                                      MediaKeySystemStatus aStatus)
+{
+  RequestMediaKeySystemAccessNotification data;
+  data.mKeySystem = aKeySystem;
+  data.mStatus = aStatus;
+  nsAutoString json;
+  data.ToJSON(json);
+  EME_LOG("MediaKeySystemAccess::NotifyObservers() %s", NS_ConvertUTF16toUTF8(json).get());
+  nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
+  if (obs) {
+    obs->NotifyObservers(aWindow, "mediakeys-request", json.get());
+  }
+}
+
+} // namespace dom
+} // namespace mozilla