Implement robustness strings in requestMediaKeySystemAccess().

BUG=442586,460616

Review URL: https://codereview.chromium.org/1005903003

Cr-Commit-Position: refs/heads/master@{#322219}

15 files changed, 640 insertions, 288 deletions

diff --git a/chrome/renderer/media/chrome_key_systems.cc b/chrome/renderer/media/chrome_key_systems.cc
index 5307481..33fea4a 100644
--- a/chrome/renderer/media/chrome_key_systems.cc
+++ b/chrome/renderer/media/chrome_key_systems.cc
@@ -75,22 +75,22 @@ static void AddExternalClearKey(
   KeySystemInfo info;
   info.key_system = kExternalClearKeyKeySystem;
 
-  info.supported_codecs = media::EME_CODEC_WEBM_ALL;
   info.supported_init_data_types =
       media::EME_INIT_DATA_TYPE_WEBM | media::EME_INIT_DATA_TYPE_KEYIDS;
+  info.supported_codecs = media::EME_CODEC_WEBM_ALL;
 #if defined(USE_PROPRIETARY_CODECS)
-  info.supported_codecs |= media::EME_CODEC_MP4_ALL;
   info.supported_init_data_types |= media::EME_INIT_DATA_TYPE_CENC;
+  info.supported_codecs |= media::EME_CODEC_MP4_ALL;
 #endif  // defined(USE_PROPRIETARY_CODECS)
 
+  info.max_audio_robustness = media::EmeRobustness::EMPTY;
+  info.max_video_robustness = media::EmeRobustness::EMPTY;
+
   // Persistent sessions are faked.
   info.persistent_license_support = media::EME_SESSION_TYPE_SUPPORTED;
   info.persistent_release_message_support =
       media::EME_SESSION_TYPE_NOT_SUPPORTED;
-  // TODO(sandersd): Using ALWAYS_ENABLED prevents "not-allowed" from
-  // succeeding. Change this to REQUESTABLE once the state can be blocked.
-  // http://crbug.com/457482
-  info.persistent_state_support = media::EME_FEATURE_ALWAYS_ENABLED;
+  info.persistent_state_support = media::EME_FEATURE_REQUESTABLE;
   info.distinctive_identifier_support = media::EME_FEATURE_NOT_SUPPORTED;
 
   info.pepper_type = kExternalClearKeyPepperType;
@@ -193,24 +193,21 @@ static void AddPepperBasedWidevine(
   cdm::AddWidevineWithCodecs(
       cdm::WIDEVINE, supported_codecs,
 #if defined(OS_CHROMEOS)
-      // Persistent licenses are supported if remote attestation succeeds.
-      media::EME_SESSION_TYPE_SUPPORTED_WITH_PERMISSION,
-      media::EME_SESSION_TYPE_NOT_SUPPORTED,  // Persistent release message.
-      // TODO(sandersd): Using ALWAYS_ENABLED prevents "not-allowed" from
-      // succeeding. Change this to REQUESTABLE once the state can be blocked.
-      // http://crbug.com/457482
-      media::EME_FEATURE_ALWAYS_ENABLED,  // Persistent state.
-      // A distinctive identifier will be available if remote attestation
-      // succeeds.
-      media::EME_FEATURE_REQUESTABLE_WITH_PERMISSION,
+      media::EmeRobustness::HW_SECURE_ALL,     // Maximum audio robustness.
+      media::EmeRobustness::HW_SECURE_ALL,     // Maximim video robustness.
+      // persistent-license.
+      media::EME_SESSION_TYPE_SUPPORTED_WITH_IDENTIFIER,
+      media::EME_SESSION_TYPE_NOT_SUPPORTED,   // persistent-release-message.
+      media::EME_FEATURE_REQUESTABLE,          // Persistent state.
+      // Distinctive identifier.
+      media::EME_FEATURE_REQUESTABLE_WITH_IDENTIFIER,
 #else   // (Desktop)
-      media::EME_SESSION_TYPE_NOT_SUPPORTED,  // Persistent license.
-      media::EME_SESSION_TYPE_NOT_SUPPORTED,  // Persistent release message.
-      // TODO(sandersd): Using ALWAYS_ENABLED prevents "not-allowed" from
-      // succeeding. Change this to REQUESTABLE once the state can be blocked.
-      // http://crbug.com/457482
-      media::EME_FEATURE_ALWAYS_ENABLED,  // Persistent state.
-      media::EME_FEATURE_NOT_SUPPORTED,   // Distinctive identifier.
+      media::EmeRobustness::SW_SECURE_CRYPTO,  // Maximum audio robustness.
+      media::EmeRobustness::SW_SECURE_DECODE,  // Maximum video robustness.
+      media::EME_SESSION_TYPE_NOT_SUPPORTED,   // persistent-license.
+      media::EME_SESSION_TYPE_NOT_SUPPORTED,   // persistent-release-message.
+      media::EME_FEATURE_REQUESTABLE,          // Persistent state.
+      media::EME_FEATURE_NOT_SUPPORTED,        // Distinctive identifier.
 #endif  // defined(OS_CHROMEOS)
       concrete_key_systems);
 }
diff --git a/chromecast/renderer/key_systems_cast.cc b/chromecast/renderer/key_systems_cast.cc
index 246d6ad..995092d 100644
--- a/chromecast/renderer/key_systems_cast.cc
+++ b/chromecast/renderer/key_systems_cast.cc
@@ -22,9 +22,11 @@ void AddKeySystemWithCodecs(
     std::vector<::media::KeySystemInfo>* key_systems_info) {
   ::media::KeySystemInfo info;
   info.key_system = key_system_name;
+  info.supported_init_data_types = ::media::EME_INIT_DATA_TYPE_CENC;
   info.supported_codecs =
       ::media::EME_CODEC_MP4_AAC | ::media::EME_CODEC_MP4_AVC1;
-  info.supported_init_data_types = ::media::EME_INIT_DATA_TYPE_CENC;
+  info.max_audio_robustness = ::media::EmeRobustness::EMPTY;
+  info.max_video_robustness = ::media::EmeRobustness::EMPTY;
   info.persistent_license_support = ::media::EME_SESSION_TYPE_NOT_SUPPORTED;
   info.persistent_release_message_support =
       ::media::EME_SESSION_TYPE_NOT_SUPPORTED;
@@ -39,8 +41,10 @@ void AddChromecastKeySystems(
   AddWidevineWithCodecs(
       cdm::WIDEVINE,
       ::media::EME_CODEC_MP4_AAC | ::media::EME_CODEC_MP4_AVC1,
-      ::media::EME_SESSION_TYPE_NOT_SUPPORTED,  // Persistent license.
-      ::media::EME_SESSION_TYPE_NOT_SUPPORTED,  // Persistent release message.
+      ::media::EmeRobustness::HW_SECURE_ALL,    // Max audio robustness.
+      ::media::EmeRobustness::HW_SECURE_ALL,    // Max video robustness.
+      ::media::EME_SESSION_TYPE_NOT_SUPPORTED,  // persistent-license.
+      ::media::EME_SESSION_TYPE_NOT_SUPPORTED,  // persistent-release-message.
       ::media::EME_FEATURE_NOT_SUPPORTED,       // Persistent state.
       ::media::EME_FEATURE_ALWAYS_ENABLED,      // Distinctive identifier.
       key_systems_info);
diff --git a/components/cdm/renderer/android_key_systems.cc b/components/cdm/renderer/android_key_systems.cc
index d1e0f2a..e773656 100644
--- a/components/cdm/renderer/android_key_systems.cc
+++ b/components/cdm/renderer/android_key_systems.cc
@@ -7,14 +7,17 @@
 #include <string>
 #include <vector>
 
+#include "base/command_line.h"
 #include "base/logging.h"
 #include "components/cdm/common/cdm_messages_android.h"
 #include "components/cdm/renderer/widevine_key_systems.h"
 #include "content/public/renderer/render_thread.h"
 #include "media/base/eme_constants.h"
+#include "media/base/media_switches.h"
 
 #include "widevine_cdm_version.h"  // In SHARED_INTERMEDIATE_DIR.
 
+using media::EmeRobustness;
 using media::KeySystemInfo;
 using media::SupportedCodecs;
 
@@ -39,24 +42,48 @@ static SupportedKeySystemResponse QueryKeySystemSupport(
 void AddAndroidWidevine(std::vector<KeySystemInfo>* concrete_key_systems) {
   SupportedKeySystemResponse response = QueryKeySystemSupport(
       kWidevineKeySystem);
-  if (response.compositing_codecs != media::EME_CODEC_NONE) {
+
+  // When creating the WIDEVINE key system, BrowserCdmFactoryAndroid configures
+  // the CDM's security level based on the --mediadrm-enable-non-compositing
+  // flag (L1 if the flag is enabled, L3 otherwise). Therefore the supported
+  // codec/robustenss combinations depend on that flag.
+  // TODO(sandersd): For unprefixed, set the security level based on the
+  // requested robustness instead of the flag. http://crbug.com/467779
+  SupportedCodecs codecs = response.compositing_codecs;
+  EmeRobustness max_audio_robustness = EmeRobustness::SW_SECURE_CRYPTO;
+  EmeRobustness max_video_robustness = EmeRobustness::SW_SECURE_CRYPTO;
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kMediaDrmEnableNonCompositing)) {
+    codecs = response.non_compositing_codecs;
+    max_audio_robustness = EmeRobustness::HW_SECURE_CRYPTO;
+    max_video_robustness = EmeRobustness::HW_SECURE_ALL;
+  }
+  if (codecs != media::EME_CODEC_NONE) {
     AddWidevineWithCodecs(
         WIDEVINE,
-        static_cast<SupportedCodecs>(response.compositing_codecs),
-        media::EME_SESSION_TYPE_NOT_SUPPORTED,  // Persistent license.
-        media::EME_SESSION_TYPE_NOT_SUPPORTED,  // Persistent release message.
+        codecs,
+        max_audio_robustness,
+        max_video_robustness,
+        media::EME_SESSION_TYPE_NOT_SUPPORTED,  // persistent-license.
+        media::EME_SESSION_TYPE_NOT_SUPPORTED,  // persistent-release-message.
         media::EME_FEATURE_NOT_SUPPORTED,       // Persistent state.
         media::EME_FEATURE_ALWAYS_ENABLED,      // Distinctive identifier.
         concrete_key_systems);
   }
 
+  // For compatibility with the prefixed API, register a separate L1 key system.
+  // When creating the WIDEVINE_HR_NON_COMPOSITING key system,
+  // BrowserCdmFactoryAndroid does not configure the CDM's security level (that
+  // is, leaves it as L1); therefore only secure codecs are supported.
+  // TODO(ddorwin): Remove with unprefixed. http://crbug.com/249976
   if (response.non_compositing_codecs != media::EME_CODEC_NONE) {
-    // TODO(ddorwin): Remove with unprefixed. http://crbug.com/249976
     AddWidevineWithCodecs(
         WIDEVINE_HR_NON_COMPOSITING,
-        static_cast<SupportedCodecs>(response.non_compositing_codecs),
-        media::EME_SESSION_TYPE_NOT_SUPPORTED,  // Persistent license.
-        media::EME_SESSION_TYPE_NOT_SUPPORTED,  // Persistent release message.
+        response.non_compositing_codecs,
+        EmeRobustness::HW_SECURE_CRYPTO,        // Max audio robustness.
+        EmeRobustness::HW_SECURE_ALL,           // Max video robustness.
+        media::EME_SESSION_TYPE_NOT_SUPPORTED,  // persistent-license.
+        media::EME_SESSION_TYPE_NOT_SUPPORTED,  // persistent-release-message.
         media::EME_FEATURE_NOT_SUPPORTED,       // Persistent state.
         media::EME_FEATURE_ALWAYS_ENABLED,      // Distinctive identifier.
         concrete_key_systems);
@@ -85,6 +112,8 @@ void AddAndroidPlatformKeySystems(
       if (response.compositing_codecs & media::EME_CODEC_MP4_ALL)
         info.supported_init_data_types |= media::EME_INIT_DATA_TYPE_CENC;
 #endif  // defined(USE_PROPRIETARY_CODECS)
+      info.max_audio_robustness = EmeRobustness::EMPTY;
+      info.max_video_robustness = EmeRobustness::EMPTY;
       // Assume the worst case (from a user point of view).
       info.persistent_license_support = media::EME_SESSION_TYPE_NOT_SUPPORTED;
       info.persistent_release_message_support =
diff --git a/components/cdm/renderer/widevine_key_systems.cc b/components/cdm/renderer/widevine_key_systems.cc
index 037df1b..ec38ab6 100644
--- a/components/cdm/renderer/widevine_key_systems.cc
+++ b/components/cdm/renderer/widevine_key_systems.cc
@@ -29,6 +29,8 @@ static std::string GetDirectParentName(std::string name) {
 void AddWidevineWithCodecs(
     WidevineCdmType widevine_cdm_type,
     SupportedCodecs supported_codecs,
+    media::EmeRobustness max_audio_robustness,
+    media::EmeRobustness max_video_robustness,
     media::EmeSessionTypeSupport persistent_license_support,
     media::EmeSessionTypeSupport persistent_release_message_support,
     media::EmeFeatureSupport persistent_state_support,
@@ -66,6 +68,8 @@ void AddWidevineWithCodecs(
     info.supported_init_data_types |= media::EME_INIT_DATA_TYPE_CENC;
 #endif  // defined(USE_PROPRIETARY_CODECS)
 
+  info.max_audio_robustness = max_audio_robustness;
+  info.max_video_robustness = max_video_robustness;
   info.persistent_license_support = persistent_license_support;
   info.persistent_release_message_support = persistent_release_message_support;
   info.persistent_state_support = persistent_state_support;
diff --git a/components/cdm/renderer/widevine_key_systems.h b/components/cdm/renderer/widevine_key_systems.h
index 15c55da..dc05bb8 100644
--- a/components/cdm/renderer/widevine_key_systems.h
+++ b/components/cdm/renderer/widevine_key_systems.h
@@ -22,6 +22,8 @@ enum WidevineCdmType {
 void AddWidevineWithCodecs(
     WidevineCdmType widevine_cdm_type,
     media::SupportedCodecs supported_codecs,
+    media::EmeRobustness max_audio_robustness,
+    media::EmeRobustness max_video_robustness,
     media::EmeSessionTypeSupport persistent_license_support,
     media::EmeSessionTypeSupport persistent_release_message_support,
     media::EmeFeatureSupport persistent_state_support,
diff --git a/content/renderer/media/render_media_client_unittest.cc b/content/renderer/media/render_media_client_unittest.cc
index 2366156..7ac253e 100644
--- a/content/renderer/media/render_media_client_unittest.cc
+++ b/content/renderer/media/render_media_client_unittest.cc
@@ -27,6 +27,8 @@ class TestContentRendererClient : public ContentRendererClient {
     // TODO(sandersd): Was this supposed to be added to the list?
     media::KeySystemInfo key_system_info;
     key_system_info.key_system = "test.keysystem";
+    key_system_info.max_audio_robustness = media::EmeRobustness::EMPTY;
+    key_system_info.max_video_robustness = media::EmeRobustness::EMPTY;
     key_system_info.persistent_license_support =
         media::EME_SESSION_TYPE_NOT_SUPPORTED;
     key_system_info.persistent_release_message_support =
@@ -40,6 +42,8 @@ class TestContentRendererClient : public ContentRendererClient {
     if (is_extra_key_system_enabled_) {
       media::KeySystemInfo wv_key_system_info;
       wv_key_system_info.key_system = kWidevineKeySystem;
+      wv_key_system_info.max_audio_robustness = media::EmeRobustness::EMPTY;
+      wv_key_system_info.max_video_robustness = media::EmeRobustness::EMPTY;
       wv_key_system_info.persistent_license_support =
           media::EME_SESSION_TYPE_NOT_SUPPORTED;
       wv_key_system_info.persistent_release_message_support =
diff --git a/media/base/android/browser_cdm_factory_android.cc b/media/base/android/browser_cdm_factory_android.cc
index e116863..614c8d1 100644
--- a/media/base/android/browser_cdm_factory_android.cc
+++ b/media/base/android/browser_cdm_factory_android.cc
@@ -34,7 +34,7 @@ scoped_ptr<BrowserCdm> BrowserCdmFactoryAndroid::CreateBrowserCdm(
   }
 
   // TODO(xhwang/ddorwin): Pass the security level from key system.
-  // http://crbug.com/459400
+  // http://crbug.com/467779
   if (key_system == kWidevineKeySystem) {
     MediaDrmBridge::SecurityLevel security_level =
         MediaDrmBridge::SECURITY_LEVEL_3;
diff --git a/media/base/eme_constants.h b/media/base/eme_constants.h
index 2f8f033..7882fae 100644
--- a/media/base/eme_constants.h
+++ b/media/base/eme_constants.h
@@ -55,32 +55,75 @@ enum EmeSessionTypeSupport {
   EME_SESSION_TYPE_INVALID,
   // The session type is not supported.
   EME_SESSION_TYPE_NOT_SUPPORTED,
-  // The session type is supported if the encrypted media permission is granted.
-  EME_SESSION_TYPE_SUPPORTED_WITH_PERMISSION,
+  // The session type is supported if a distinctive identifier is available.
+  EME_SESSION_TYPE_SUPPORTED_WITH_IDENTIFIER,
   // The session type is always supported.
   EME_SESSION_TYPE_SUPPORTED,
 };
 
+// Used to declare support for distinctive identifier and persistent state.
 enum EmeFeatureSupport {
   // Invalid default value.
   EME_FEATURE_INVALID,
   // Access to the feature is not supported at all.
   EME_FEATURE_NOT_SUPPORTED,
-  // Access to the feature may be requested if the encrypted media permission is
-  // granted.
-  EME_FEATURE_REQUESTABLE_WITH_PERMISSION,
+  // Access to the feature may be requested if a distinctive identifier is
+  // available. (This is the correct choice for declaring support for a
+  // requestable distinctive identifier.)
+  EME_FEATURE_REQUESTABLE_WITH_IDENTIFIER,
   // Access to the feature may be requested.
   EME_FEATURE_REQUESTABLE,
   // Access to the feature cannot be blocked.
   EME_FEATURE_ALWAYS_ENABLED,
 };
 
+// Used to query support for distinctive identifier and persistent state.
 enum EmeFeatureRequirement {
   EME_FEATURE_NOT_ALLOWED,
   EME_FEATURE_OPTIONAL,
   EME_FEATURE_REQUIRED,
 };
 
+enum class EmeMediaType {
+  AUDIO,
+  VIDEO,
+};
+
+// Robustness values understood by KeySystems.
+// Note: KeySystems expects this ordering (in GetRobustnessConfigRule()),
+// changes may be required there if this list changes.
+enum class EmeRobustness {
+  INVALID,
+  EMPTY,
+  SW_SECURE_CRYPTO,
+  SW_SECURE_DECODE,
+  HW_SECURE_CRYPTO,
+  HW_SECURE_DECODE,
+  HW_SECURE_ALL,
+};
+
+// Configuration rules indicate the configuration state required to support a
+// configuration option (note: a configuration option may be disallowing a
+// feature). Configuration rules are used to answer queries about distinctive
+// identifier, persistent state, and robustness requirements, as well as to
+// describe support for different session types.
+//
+// If in the future there are reasons to request user permission other than
+// access to a distinctive identifier, then additional rules should be added.
+// Rules are implemented in ConfigState and are otherwise opaque.
+enum class EmeConfigRule {
+  // The configuration option is not supported.
+  NOT_SUPPORTED,
+  // The configuration option is supported if a distinctive identifier is
+  // available.
+  IDENTIFIER_REQUIRED,
+  // The configuration option is supported, but the user experience may be
+  // improved if a distinctive identifier is available.
+  IDENTIFIER_RECOMMENDED,
+  // The configuration option is supported without conditions.
+  SUPPORTED,
+};
+
 }  // namespace media
 
 #endif  // MEDIA_BASE_EME_CONSTANTS_H_
diff --git a/media/base/key_system_info.cc b/media/base/key_system_info.cc
index b656f0f..55927790 100644
--- a/media/base/key_system_info.cc
+++ b/media/base/key_system_info.cc
@@ -9,6 +9,8 @@ namespace media {
 KeySystemInfo::KeySystemInfo()
     : supported_init_data_types(EME_INIT_DATA_TYPE_NONE),
       supported_codecs(EME_CODEC_NONE),
+      max_audio_robustness(EmeRobustness::INVALID),
+      max_video_robustness(EmeRobustness::INVALID),
       persistent_license_support(EME_SESSION_TYPE_INVALID),
       persistent_release_message_support(EME_SESSION_TYPE_INVALID),
       persistent_state_support(EME_FEATURE_INVALID),
diff --git a/media/base/key_system_info.h b/media/base/key_system_info.h
index e66d8be..218cebd 100644
--- a/media/base/key_system_info.h
+++ b/media/base/key_system_info.h
@@ -35,13 +35,10 @@ struct MEDIA_EXPORT KeySystemInfo {
 
   std::string key_system;
 
-  // Specifies registered initialization data types supported by |key_system|.
   SupportedInitDataTypes supported_init_data_types;
-
-  // Specifies codecs supported by |key_system|.
   SupportedCodecs supported_codecs;
-
-  // Specifies session types and features supported by |key_system|.
+  EmeRobustness max_audio_robustness;
+  EmeRobustness max_video_robustness;
   EmeSessionTypeSupport persistent_license_support;
   EmeSessionTypeSupport persistent_release_message_support;
   EmeFeatureSupport persistent_state_support;
diff --git a/media/base/key_systems.cc b/media/base/key_systems.cc
index 92bcc38e..bf33dcc 100644
--- a/media/base/key_systems.cc
+++ b/media/base/key_systems.cc
@@ -76,6 +76,39 @@ static NamedCodec kCodecStrings[] = {
 #endif  // defined(USE_PROPRIETARY_CODECS)
 };
 
+static EmeConfigRule ConvertSessionTypeSupport(
+    EmeSessionTypeSupport support) {
+  switch (support) {
+    case EME_SESSION_TYPE_INVALID:
+      NOTREACHED();
+      return EmeConfigRule::NOT_SUPPORTED;
+    case EME_SESSION_TYPE_NOT_SUPPORTED:
+      return EmeConfigRule::NOT_SUPPORTED;
+    case EME_SESSION_TYPE_SUPPORTED_WITH_IDENTIFIER:
+      return EmeConfigRule::IDENTIFIER_REQUIRED;
+    case EME_SESSION_TYPE_SUPPORTED:
+      return EmeConfigRule::SUPPORTED;
+  }
+  NOTREACHED();
+  return EmeConfigRule::NOT_SUPPORTED;
+}
+
+static EmeRobustness ConvertRobustness(const std::string& robustness) {
+  if (robustness.empty())
+    return EmeRobustness::EMPTY;
+  if (robustness == "SW_SECURE_CRYPTO")
+    return EmeRobustness::SW_SECURE_CRYPTO;
+  if (robustness == "SW_SECURE_DECODE")
+    return EmeRobustness::SW_SECURE_DECODE;
+  if (robustness == "HW_SECURE_CRYPTO")
+    return EmeRobustness::HW_SECURE_CRYPTO;
+  if (robustness == "HW_SECURE_DECODE")
+    return EmeRobustness::HW_SECURE_DECODE;
+  if (robustness == "HW_SECURE_ALL")
+    return EmeRobustness::HW_SECURE_ALL;
+  return EmeRobustness::INVALID;
+}
+
 static void AddClearKey(std::vector<KeySystemInfo>* concrete_key_systems) {
   KeySystemInfo info;
   info.key_system = kClearKeyKeySystem;
@@ -103,6 +136,8 @@ static void AddClearKey(std::vector<KeySystemInfo>* concrete_key_systems) {
   info.supported_codecs |= EME_CODEC_MP4_ALL;
 #endif  // defined(USE_PROPRIETARY_CODECS)
 
+  info.max_audio_robustness = EmeRobustness::EMPTY;
+  info.max_video_robustness = EmeRobustness::EMPTY;
   info.persistent_license_support = EME_SESSION_TYPE_NOT_SUPPORTED;
   info.persistent_release_message_support = EME_SESSION_TYPE_NOT_SUPPORTED;
   info.persistent_state_support = EME_FEATURE_NOT_SUPPORTED;
@@ -191,23 +226,24 @@ class KeySystems {
   std::string GetPepperType(const std::string& concrete_key_system);
 #endif
 
-  bool IsPersistentLicenseSessionSupported(
+  EmeConfigRule GetRobustnessConfigRule(
       const std::string& key_system,
-      bool is_permission_granted);
+      EmeMediaType media_type,
+      const std::string& requested_robustness);
 
-  bool IsPersistentReleaseMessageSessionSupported(
-      const std::string& key_system,
-      bool is_permission_granted);
+  EmeConfigRule GetPersistentLicenseSessionConfigRule(
+      const std::string& key_system);
 
-  bool IsPersistentStateRequirementSupported(
+  EmeConfigRule GetPersistentReleaseMessageSessionConfigRule(
+      const std::string& key_system);
+
+  EmeConfigRule GetPersistentStateConfigRule(
       const std::string& key_system,
-      EmeFeatureRequirement requirement,
-      bool is_permission_granted);
+      EmeFeatureRequirement requirement);
 
-  bool IsDistinctiveIdentifierRequirementSupported(
+  EmeConfigRule GetDistinctiveIdentifierConfigRule(
       const std::string& key_system,
-      EmeFeatureRequirement requirement,
-      bool is_permission_granted);
+      EmeFeatureRequirement requirement);
 
   void AddContainerMask(const std::string& container, uint32 mask);
   void AddCodecMask(const std::string& codec, uint32 mask);
@@ -394,45 +430,71 @@ void KeySystems::AddConcreteSupportedKeySystems(
 
   for (const KeySystemInfo& info : concrete_key_systems) {
     DCHECK(!info.key_system.empty());
-    DCHECK_NE(info.persistent_license_support, EME_SESSION_TYPE_INVALID);
-    DCHECK_NE(info.persistent_release_message_support,
-              EME_SESSION_TYPE_INVALID);
-    // TODO(sandersd): Add REQUESTABLE and REQUESTABLE_WITH_PERMISSION for
-    // persistent_state_support once we can block access per-CDM-instance
-    // (http://crbug.com/457482).
-    DCHECK(info.persistent_state_support == EME_FEATURE_NOT_SUPPORTED ||
-           info.persistent_state_support == EME_FEATURE_ALWAYS_ENABLED);
-// TODO(sandersd): Allow REQUESTABLE_WITH_PERMISSION for all key systems on
-// all platforms once we have proper enforcement (http://crbug.com/457482).
-// On Chrome OS, an ID will not be used without permission, but we cannot
-// currently prevent the CDM from requesting the permission again when no
-// there was no initial prompt. Thus, we block "not-allowed" below.
-#if defined(OS_CHROMEOS)
-    DCHECK(info.distinctive_identifier_support == EME_FEATURE_NOT_SUPPORTED ||
-           (info.distinctive_identifier_support ==
-                EME_FEATURE_REQUESTABLE_WITH_PERMISSION &&
-            info.key_system == kWidevineKeySystem) ||
-           info.distinctive_identifier_support == EME_FEATURE_ALWAYS_ENABLED);
-#else
-    DCHECK(info.distinctive_identifier_support == EME_FEATURE_NOT_SUPPORTED ||
-           info.distinctive_identifier_support == EME_FEATURE_ALWAYS_ENABLED);
-#endif
+    DCHECK(info.max_audio_robustness != EmeRobustness::INVALID);
+    DCHECK(info.max_video_robustness != EmeRobustness::INVALID);
+    DCHECK(info.persistent_license_support != EME_SESSION_TYPE_INVALID);
+    DCHECK(info.persistent_release_message_support != EME_SESSION_TYPE_INVALID);
+    DCHECK(info.persistent_state_support != EME_FEATURE_INVALID);
+    DCHECK(info.distinctive_identifier_support != EME_FEATURE_INVALID);
+
+    // Supporting persistent state is a prerequsite for supporting persistent
+    // sessions.
     if (info.persistent_state_support == EME_FEATURE_NOT_SUPPORTED) {
-      DCHECK_EQ(info.persistent_license_support,
-                EME_SESSION_TYPE_NOT_SUPPORTED);
-      DCHECK_EQ(info.persistent_release_message_support,
-                EME_SESSION_TYPE_NOT_SUPPORTED);
+      DCHECK(info.persistent_license_support == EME_SESSION_TYPE_NOT_SUPPORTED);
+      DCHECK(info.persistent_release_message_support ==
+             EME_SESSION_TYPE_NOT_SUPPORTED);
     }
-    DCHECK(!IsSupportedKeySystem(info.key_system))
-        << "Key system '" << info.key_system << "' already registered";
-    DCHECK(!parent_key_system_map_.count(info.key_system))
-        <<  "'" << info.key_system << "' is already registered as a parent";
+    else if (info.persistent_state_support ==
+             EME_FEATURE_REQUESTABLE_WITH_IDENTIFIER) {
+      // Must be either NOT_SUPPORTED or SUPPORTED_WITH_IDENTIFIER.
+      DCHECK(info.persistent_license_support != EME_SESSION_TYPE_SUPPORTED);
+      DCHECK(info.persistent_release_message_support !=
+             EME_SESSION_TYPE_SUPPORTED);
+    }
+
+    // persistent-release-message sessions are not currently supported.
+    // http://crbug.com/448888
+    DCHECK(info.persistent_release_message_support ==
+           EME_SESSION_TYPE_NOT_SUPPORTED);
+
+    // Because an optional persistent state value is resolved after an optional
+    // distinctive identifier, persistent state requiring a distinctive
+    // identifier may not resolve correctly.
+    DCHECK(info.persistent_state_support !=
+           EME_FEATURE_REQUESTABLE_WITH_IDENTIFIER);
+
+    // If supported, distinctive identifiers always require permission.
+    DCHECK(info.distinctive_identifier_support != EME_FEATURE_REQUESTABLE);
+
+    // If distinctive identifiers are not supported, then no other features can
+    // require them.
+    if (info.distinctive_identifier_support == EME_FEATURE_NOT_SUPPORTED) {
+      DCHECK(info.persistent_license_support !=
+             EME_SESSION_TYPE_SUPPORTED_WITH_IDENTIFIER);
+      DCHECK(info.persistent_release_message_support !=
+             EME_SESSION_TYPE_SUPPORTED_WITH_IDENTIFIER);
+    }
+
+    // Distinctive identifiers and persistent state can only be reliably blocked
+    // (and therefore be safely configurable) for Pepper-hosted key systems. For
+    // other platforms, only non-configurable values are valid.
+    bool can_block = false;
 #if defined(ENABLE_PEPPER_CDMS)
     DCHECK_EQ(info.use_aes_decryptor, info.pepper_type.empty());
+    can_block = !info.pepper_type.empty();
 #endif
+    if (!can_block) {
+      DCHECK(info.distinctive_identifier_support == EME_FEATURE_NOT_SUPPORTED ||
+             info.distinctive_identifier_support == EME_FEATURE_ALWAYS_ENABLED);
+      DCHECK(info.persistent_state_support == EME_FEATURE_NOT_SUPPORTED ||
+             info.persistent_state_support == EME_FEATURE_ALWAYS_ENABLED);
+    }
 
+    DCHECK(!IsSupportedKeySystem(info.key_system))
+        << "Key system '" << info.key_system << "' already registered";
+    DCHECK(!parent_key_system_map_.count(info.key_system))
+        <<  "'" << info.key_system << "' is already registered as a parent";
     concrete_key_system_map_[info.key_system] = info;
-
     if (!info.parent_key_system.empty()) {
       DCHECK(!IsConcreteSupportedKeySystem(info.parent_key_system))
           << "Parent '" << info.parent_key_system << "' "
@@ -620,132 +682,172 @@ std::string KeySystems::GetPepperType(const std::string& concrete_key_system) {
 }
 #endif
 
-bool KeySystems::IsPersistentLicenseSessionSupported(
+EmeConfigRule KeySystems::GetRobustnessConfigRule(
     const std::string& key_system,
-    bool is_permission_granted) {
+    EmeMediaType media_type,
+    const std::string& requested_robustness) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
+  EmeRobustness robustness = ConvertRobustness(requested_robustness);
+  if (robustness == EmeRobustness::INVALID)
+    return EmeConfigRule::NOT_SUPPORTED;
+  if (robustness == EmeRobustness::EMPTY)
+    return EmeConfigRule::SUPPORTED;
+
   KeySystemInfoMap::const_iterator key_system_iter =
       concrete_key_system_map_.find(key_system);
   if (key_system_iter == concrete_key_system_map_.end()) {
     NOTREACHED();
-    return false;
+    return EmeConfigRule::NOT_SUPPORTED;
   }
 
-  switch (key_system_iter->second.persistent_license_support) {
-    case EME_SESSION_TYPE_INVALID:
-      NOTREACHED();
-      return false;
-    case EME_SESSION_TYPE_NOT_SUPPORTED:
-      return false;
-    case EME_SESSION_TYPE_SUPPORTED_WITH_PERMISSION:
-      return is_permission_granted;
-    case EME_SESSION_TYPE_SUPPORTED:
-      return true;
+  EmeRobustness max_robustness = EmeRobustness::INVALID;
+  switch (media_type) {
+    case EmeMediaType::AUDIO:
+      max_robustness = key_system_iter->second.max_audio_robustness;
+      break;
+    case EmeMediaType::VIDEO:
+      max_robustness = key_system_iter->second.max_video_robustness;
+      break;
   }
 
-  NOTREACHED();
-  return false;
+  // We can compare robustness levels whenever they are not HW_SECURE_CRYPTO
+  // and SW_SECURE_DECODE in some order. If they are exactly those two then the
+  // robustness requirement is not supported.
+  if ((max_robustness == EmeRobustness::HW_SECURE_CRYPTO &&
+       robustness == EmeRobustness::SW_SECURE_DECODE) ||
+      (max_robustness == EmeRobustness::SW_SECURE_DECODE &&
+       robustness == EmeRobustness::HW_SECURE_CRYPTO) ||
+      robustness > max_robustness) {
+    return EmeConfigRule::NOT_SUPPORTED;
+  }
+
+#if defined(OS_CHROMEOS)
+  if (key_system == kWidevineKeySystem) {
+    // Hardware security requires remote attestation.
+    if (robustness >= EmeRobustness::HW_SECURE_CRYPTO)
+      return EmeConfigRule::IDENTIFIER_REQUIRED;
+
+    // For video, recommend remote attestation if HW_SECURE_ALL is available,
+    // because it enables hardware accelerated decoding.
+    // TODO(sandersd): Only do this when hardware accelerated decoding is
+    // available for the requested codecs.
+    if (media_type == EmeMediaType::VIDEO &&
+        max_robustness == EmeRobustness::HW_SECURE_ALL) {
+      return EmeConfigRule::IDENTIFIER_RECOMMENDED;
+    }
+  }
+#endif  // defined(OS_CHROMEOS)
+
+  return EmeConfigRule::SUPPORTED;
 }
 
-bool KeySystems::IsPersistentReleaseMessageSessionSupported(
-    const std::string& key_system,
-    bool is_permission_granted) {
+EmeConfigRule KeySystems::GetPersistentLicenseSessionConfigRule(
+    const std::string& key_system) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   KeySystemInfoMap::const_iterator key_system_iter =
       concrete_key_system_map_.find(key_system);
   if (key_system_iter == concrete_key_system_map_.end()) {
     NOTREACHED();
-    return false;
+    return EmeConfigRule::NOT_SUPPORTED;
   }
+  return ConvertSessionTypeSupport(
+      key_system_iter->second.persistent_license_support);
+}
 
-  switch (key_system_iter->second.persistent_release_message_support) {
-    case EME_SESSION_TYPE_INVALID:
-      NOTREACHED();
-      return false;
-    case EME_SESSION_TYPE_NOT_SUPPORTED:
-      return false;
-    case EME_SESSION_TYPE_SUPPORTED_WITH_PERMISSION:
-      return is_permission_granted;
-    case EME_SESSION_TYPE_SUPPORTED:
-      return true;
-  }
+EmeConfigRule KeySystems::GetPersistentReleaseMessageSessionConfigRule(
+    const std::string& key_system) {
+  DCHECK(thread_checker_.CalledOnValidThread());
 
-  NOTREACHED();
-  return false;
+  KeySystemInfoMap::const_iterator key_system_iter =
+      concrete_key_system_map_.find(key_system);
+  if (key_system_iter == concrete_key_system_map_.end()) {
+    NOTREACHED();
+    return EmeConfigRule::NOT_SUPPORTED;
+  }
+  return ConvertSessionTypeSupport(
+      key_system_iter->second.persistent_release_message_support);
 }
 
-bool KeySystems::IsPersistentStateRequirementSupported(
+EmeConfigRule KeySystems::GetPersistentStateConfigRule(
     const std::string& key_system,
-    EmeFeatureRequirement requirement,
-    bool is_permission_granted) {
+    EmeFeatureRequirement requirement) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   KeySystemInfoMap::const_iterator key_system_iter =
       concrete_key_system_map_.find(key_system);
   if (key_system_iter == concrete_key_system_map_.end()) {
     NOTREACHED();
-    return false;
+    return EmeConfigRule::NOT_SUPPORTED;
   }
 
-  switch (key_system_iter->second.persistent_state_support) {
-    case EME_FEATURE_INVALID:
-      NOTREACHED();
-      return false;
-    case EME_FEATURE_NOT_SUPPORTED:
-      return requirement != EME_FEATURE_REQUIRED;
-    case EME_FEATURE_REQUESTABLE_WITH_PERMISSION:
-      return (requirement != EME_FEATURE_REQUIRED) || is_permission_granted;
-    case EME_FEATURE_REQUESTABLE:
-      return true;
-    case EME_FEATURE_ALWAYS_ENABLED:
-      // Persistent state does not require user permission, but the session
-      // types that use it might.
-      return requirement != EME_FEATURE_NOT_ALLOWED;
+  // For NOT_ALLOWED and REQUIRED, the result is as expected. For OPTIONAL, we
+  // return the least restrictive of the two rules; this guarantees that if
+  // OPTIONAL is accepted, then it can always be resolved to some value. (In
+  // fact OPTIONAL is always accepted, because the least restrictive rule is
+  // always SUPPORTED.)
+  //
+  // Note that even if permission is not required for persistent state, it may
+  // be required for specific persistent session types.
+  //
+  //                              NOT_ALLOWED    OPTIONAL   REQUIRED
+  //               NOT_SUPPORTED  SUPPORTED      SUPPORTED  NOT_SUPPORTED
+  // REQUESTABLE_WITH_IDENTIFIER  SUPPORTED      SUPPORTED  IDENTIFIER_REQ
+  //                 REQUESTABLE  SUPPORTED      SUPPORTED  SUPPORTED
+  //              ALWAYS_ENABLED  NOT_SUPPORTED  SUPPORTED  SUPPORTED
+  EmeFeatureSupport support = key_system_iter->second.persistent_state_support;
+  if (support == EME_FEATURE_NOT_SUPPORTED &&
+      requirement == EME_FEATURE_REQUIRED) {
+    return EmeConfigRule::NOT_SUPPORTED;
   }
-
-  NOTREACHED();
-  return false;
+  if (support == EME_FEATURE_ALWAYS_ENABLED &&
+      requirement == EME_FEATURE_NOT_ALLOWED) {
+    return EmeConfigRule::NOT_SUPPORTED;
+  }
+  if (support == EME_FEATURE_REQUESTABLE_WITH_IDENTIFIER &&
+      requirement == EME_FEATURE_REQUIRED) {
+    return EmeConfigRule::IDENTIFIER_REQUIRED;
+  }
+  return EmeConfigRule::SUPPORTED;
 }
 
-bool KeySystems::IsDistinctiveIdentifierRequirementSupported(
+EmeConfigRule KeySystems::GetDistinctiveIdentifierConfigRule(
     const std::string& key_system,
-    EmeFeatureRequirement requirement,
-    bool is_permission_granted) {
+    EmeFeatureRequirement requirement) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   KeySystemInfoMap::const_iterator key_system_iter =
       concrete_key_system_map_.find(key_system);
   if (key_system_iter == concrete_key_system_map_.end()) {
     NOTREACHED();
-    return false;
+    return EmeConfigRule::NOT_SUPPORTED;
   }
 
-  switch (key_system_iter->second.distinctive_identifier_support) {
-    case EME_FEATURE_INVALID:
-      NOTREACHED();
-      return false;
-    case EME_FEATURE_NOT_SUPPORTED:
-      return requirement != EME_FEATURE_REQUIRED;
-    case EME_FEATURE_REQUESTABLE_WITH_PERMISSION:
-      // TODO(sandersd): Remove this hack once crbug.com/457482 and
-      // crbug.com/460616 are addressed.
-      // We cannot currently enforce "not-allowed", so don't allow it.
-      // Note: Removing this check will expose crbug.com/460616.
-      if (requirement == EME_FEATURE_NOT_ALLOWED)
-        return false;
-      return (requirement != EME_FEATURE_REQUIRED) || is_permission_granted;
-    case EME_FEATURE_REQUESTABLE:
-      NOTREACHED();
-      return true;
-    case EME_FEATURE_ALWAYS_ENABLED:
-      // Distinctive identifiers always require user permission.
-      return (requirement != EME_FEATURE_NOT_ALLOWED) && is_permission_granted;
+  // Permission is required for REQUIRED, but not for NOT_ALLOWED. For OPTIONAL,
+  // we return the least restrictive of the two rules; this guarantees that if
+  // OPTIONAL is accepted, then it can always be resolved to some value.
+  //
+  //                              NOT_ALLOWED    OPTIONAL        REQUIRED
+  //               NOT_SUPPORTED  SUPPORTED      SUPPORTED       NOT_SUPPORTED
+  // REQUESTABLE_WITH_IDENTIFIER  SUPPORTED      SUPPORTED       IDENTIFIER_REQ
+  //              ALWAYS_ENABLED  NOT_SUPPORTED  IDENTIFIER_REQ  IDENTIFIER_REQ
+  EmeFeatureSupport support =
+      key_system_iter->second.distinctive_identifier_support;
+  DCHECK(support != EME_FEATURE_REQUESTABLE);
+  if (support == EME_FEATURE_NOT_SUPPORTED &&
+      requirement == EME_FEATURE_REQUIRED) {
+    return EmeConfigRule::NOT_SUPPORTED;
   }
-
-  NOTREACHED();
-  return false;
+  if (support == EME_FEATURE_ALWAYS_ENABLED &&
+      requirement == EME_FEATURE_NOT_ALLOWED) {
+    return EmeConfigRule::NOT_SUPPORTED;
+  }
+  if (support == EME_FEATURE_ALWAYS_ENABLED ||
+      requirement == EME_FEATURE_REQUIRED) {
+    return EmeConfigRule::IDENTIFIER_REQUIRED;
+  }
+  return EmeConfigRule::SUPPORTED;
 }
 
 void KeySystems::AddContainerMask(const std::string& container, uint32 mask) {
@@ -850,34 +952,38 @@ std::string GetPepperType(const std::string& concrete_key_system) {
 }
 #endif
 
-bool IsPersistentLicenseSessionSupported(
+EmeConfigRule GetRobustnessConfigRule(
     const std::string& key_system,
-    bool is_permission_granted) {
-  return KeySystems::GetInstance().IsPersistentLicenseSessionSupported(
-      key_system, is_permission_granted);
+    EmeMediaType media_type,
+    const std::string& robustness) {
+  return KeySystems::GetInstance().GetRobustnessConfigRule(
+      key_system, media_type, robustness);
 }
 
-bool IsPersistentReleaseMessageSessionSupported(
-    const std::string& key_system,
-    bool is_permission_granted) {
-  return KeySystems::GetInstance().IsPersistentReleaseMessageSessionSupported(
-      key_system, is_permission_granted);
+EmeConfigRule GetPersistentLicenseSessionConfigRule(
+    const std::string& key_system) {
+  return KeySystems::GetInstance().GetPersistentLicenseSessionConfigRule(
+      key_system);
+}
+
+EmeConfigRule GetPersistentReleaseMessageSessionConfigRule(
+    const std::string& key_system) {
+  return KeySystems::GetInstance().GetPersistentReleaseMessageSessionConfigRule(
+      key_system);
 }
 
-bool IsPersistentStateRequirementSupported(
+EmeConfigRule GetPersistentStateConfigRule(
     const std::string& key_system,
-    EmeFeatureRequirement requirement,
-    bool is_permission_granted) {
-  return KeySystems::GetInstance().IsPersistentStateRequirementSupported(
-      key_system, requirement, is_permission_granted);
+    EmeFeatureRequirement requirement) {
+  return KeySystems::GetInstance().GetPersistentStateConfigRule(
+      key_system, requirement);
 }
 
-bool IsDistinctiveIdentifierRequirementSupported(
+EmeConfigRule GetDistinctiveIdentifierConfigRule(
     const std::string& key_system,
-    EmeFeatureRequirement requirement,
-    bool is_permission_granted) {
-  return KeySystems::GetInstance().IsDistinctiveIdentifierRequirementSupported(
-      key_system, requirement, is_permission_granted);
+    EmeFeatureRequirement requirement) {
+  return KeySystems::GetInstance().GetDistinctiveIdentifierConfigRule(
+      key_system, requirement);
 }
 
 // These two functions are for testing purpose only. The declaration in the
diff --git a/media/base/key_systems.h b/media/base/key_systems.h
index 93317a1..9cb727f 100644
--- a/media/base/key_systems.h
+++ b/media/base/key_systems.h
@@ -85,27 +85,32 @@ MEDIA_EXPORT std::string GetPepperType(
     const std::string& concrete_key_system);
 #endif
 
-// Returns whether |key_system| supports persistent-license sessions.
-MEDIA_EXPORT bool IsPersistentLicenseSessionSupported(
+// Returns the configuration rule for supporting a robustness requirement.
+// TODO(sandersd): Also take a list of codecs, as they may affect the result.
+MEDIA_EXPORT EmeConfigRule GetRobustnessConfigRule(
     const std::string& key_system,
-    bool is_permission_granted);
+    EmeMediaType media_type,
+    const std::string& requested_robustness);
 
-// Returns whether |key_system| supports persistent-release-message sessions.
-MEDIA_EXPORT bool IsPersistentReleaseMessageSessionSupported(
-    const std::string& key_system,
-    bool is_permission_granted);
+// Returns the configuration rule for supporting persistent-license sessions.
+MEDIA_EXPORT EmeConfigRule GetPersistentLicenseSessionConfigRule(
+    const std::string& key_system);
+
+// Returns the configuration rule for supporting persistent-release-message
+// sessions.
+MEDIA_EXPORT EmeConfigRule GetPersistentReleaseMessageSessionConfigRule(
+    const std::string& key_system);
 
-// Returns whether |key_system| supports persistent state as requested.
-MEDIA_EXPORT bool IsPersistentStateRequirementSupported(
+// Returns the configuration rule for supporting a persistent state requirement.
+MEDIA_EXPORT EmeConfigRule GetPersistentStateConfigRule(
     const std::string& key_system,
-    EmeFeatureRequirement requirement,
-    bool is_permission_granted);
+    EmeFeatureRequirement requirement);
 
-// Returns whether |key_system| supports distinctive identifiers as requested.
-MEDIA_EXPORT bool IsDistinctiveIdentifierRequirementSupported(
+// Returns the configuration rule for supporting a distinctive identifier
+// requirement.
+MEDIA_EXPORT EmeConfigRule GetDistinctiveIdentifierConfigRule(
     const std::string& key_system,
-    EmeFeatureRequirement requirement,
-    bool is_permission_granted);
+    EmeFeatureRequirement requirement);
 
 #if defined(UNIT_TEST)
 // Helper functions to add container/codec types for testing purposes.
diff --git a/media/base/key_systems_unittest.cc b/media/base/key_systems_unittest.cc
index bb60e8b..9c5c46b 100644
--- a/media/base/key_systems_unittest.cc
+++ b/media/base/key_systems_unittest.cc
@@ -166,6 +166,8 @@ void TestMediaClient::AddUsesAesKeySystem(
   system.supported_codecs = EME_CODEC_WEBM_ALL;
   system.supported_codecs |= TEST_CODEC_FOO_ALL;
   system.supported_init_data_types = EME_INIT_DATA_TYPE_WEBM;
+  system.max_audio_robustness = EmeRobustness::EMPTY;
+  system.max_video_robustness = EmeRobustness::EMPTY;
   system.persistent_license_support = EME_SESSION_TYPE_NOT_SUPPORTED;
   system.persistent_release_message_support = EME_SESSION_TYPE_NOT_SUPPORTED;
   system.persistent_state_support = EME_FEATURE_NOT_SUPPORTED;
@@ -181,6 +183,8 @@ void TestMediaClient::AddExternalKeySystem(
   ext.supported_codecs = EME_CODEC_WEBM_ALL;
   ext.supported_codecs |= TEST_CODEC_FOO_ALL;
   ext.supported_init_data_types = EME_INIT_DATA_TYPE_WEBM;
+  ext.max_audio_robustness = EmeRobustness::EMPTY;
+  ext.max_video_robustness = EmeRobustness::EMPTY;
   ext.persistent_license_support = EME_SESSION_TYPE_SUPPORTED;
   ext.persistent_release_message_support = EME_SESSION_TYPE_NOT_SUPPORTED;
   ext.persistent_state_support = EME_FEATURE_ALWAYS_ENABLED;
diff --git a/media/blink/webencryptedmediaclient_impl.cc b/media/blink/webencryptedmediaclient_impl.cc
index e770c4e..d9b6c96 100644
--- a/media/blink/webencryptedmediaclient_impl.cc
+++ b/media/blink/webencryptedmediaclient_impl.cc
@@ -31,6 +31,101 @@ enum ConfigurationSupport {
   CONFIGURATION_SUPPORTED,
 };
 
+// Accumulates configuration rules to determine if a feature (additional
+// configuration rule) can be added to an accumulated configuration.
+class ConfigState {
+ public:
+  ConfigState(bool was_permission_requested, bool is_permission_granted)
+      : was_permission_requested_(was_permission_requested),
+        is_permission_granted_(is_permission_granted),
+        is_identifier_required_(false),
+        is_identifier_recommended_(false){
+  }
+
+  bool IsPermissionGranted() const {
+    return is_permission_granted_;
+  }
+
+  // Permission is possible if it has not been denied.
+  bool IsPermissionPossible() const {
+    return is_permission_granted_ || !was_permission_requested_;
+  }
+
+  bool IsIdentifierRequired() const {
+    return is_identifier_required_;
+  }
+
+  bool IsIdentifierRecommended() const {
+    return is_identifier_recommended_;
+  }
+
+  // Checks whether a rule is compatible with all previously added rules.
+  bool IsRuleSupported(EmeConfigRule rule) const {
+    switch (rule) {
+      case EmeConfigRule::NOT_SUPPORTED:
+        return false;
+      case EmeConfigRule::IDENTIFIER_REQUIRED:
+        return IsPermissionPossible();
+      case EmeConfigRule::IDENTIFIER_RECOMMENDED:
+        return true;
+      case EmeConfigRule::SUPPORTED:
+        return true;
+    }
+    NOTREACHED();
+    return false;
+  }
+
+  // Checks whether a rule is compatible with all previously added rules, and
+  // can be accepted without needing to add it to the configuration state. This
+  // allows considering more rules after the configuration state is final (that
+  // is, after distinctiveIdentifier has been resolved).
+  bool IsRuleSupportedWithCurrentState(EmeConfigRule rule) const {
+    switch (rule) {
+      case EmeConfigRule::NOT_SUPPORTED:
+        return false;
+      case EmeConfigRule::IDENTIFIER_REQUIRED:
+        return is_permission_granted_;
+      case EmeConfigRule::IDENTIFIER_RECOMMENDED:
+        return true;
+      case EmeConfigRule::SUPPORTED:
+        return true;
+    }
+    NOTREACHED();
+    return false;
+  }
+
+  // Add a rule to the accumulated configuration state.
+  void AddRule(EmeConfigRule rule) {
+    switch (rule) {
+      case EmeConfigRule::NOT_SUPPORTED:
+        return;
+      case EmeConfigRule::IDENTIFIER_REQUIRED:
+        is_identifier_required_ = true;
+        return;
+      case EmeConfigRule::IDENTIFIER_RECOMMENDED:
+        is_identifier_recommended_ = true;
+        return;
+      case EmeConfigRule::SUPPORTED:
+        return;
+    }
+    NOTREACHED();
+  }
+
+ private:
+  // Whether permission to use a distinctive identifier was requested. If set,
+  // |is_permission_granted_| represents the final decision.
+  const bool was_permission_requested_;
+
+  // Whether permission to use a distinctive identifier has been granted.
+  const bool is_permission_granted_;
+
+  // Whether a rule has been added that requires a distinctive identifier.
+  bool is_identifier_required_;
+
+  // Whether a rule has been added that recommends a distinctive identifier.
+  bool is_identifier_recommended_;
+};
+
 static bool IsSupportedContentType(const std::string& key_system,
                                    const std::string& mime_type,
                                    const std::string& codecs) {
@@ -65,23 +160,31 @@ static bool IsSupportedContentType(const std::string& key_system,
 static bool GetSupportedCapabilities(
     const std::string& key_system,
     const blink::WebVector<blink::WebMediaKeySystemMediaCapability>&
-        capabilities,
+        requested_media_capabilities,
+    EmeMediaType media_type,
     std::vector<blink::WebMediaKeySystemMediaCapability>*
-        media_type_capabilities) {
+        supported_media_capabilities,
+    ConfigState* config_state) {
   // From
   // https://w3c.github.io/encrypted-media/#get-supported-capabilities-for-media-type
-  // 1. Let accumulated capabilities be partial configuration.
-  //    (Skipped as there are no configuration-based codec restrictions.)
-  // 2. Let media type capabilities be empty.
-  DCHECK_EQ(media_type_capabilities->size(), 0ul);
-  // 3. For each value in capabilities:
-  for (size_t i = 0; i < capabilities.size(); i++) {
+  // 1. Let local accumulated capabilities be a local copy of partial
+  //    configuration.
+  //    (Skipped as we directly update |config_state|. This is safe because we
+  //    only do so when at least one requested media capability is supported.)
+  // 2. Let supported media capabilities be empty.
+  DCHECK_EQ(supported_media_capabilities->size(), 0ul);
+  // 3. For each value in requested media capabilities:
+  for (size_t i = 0; i < requested_media_capabilities.size(); i++) {
     // 3.1. Let contentType be the value's contentType member.
     // 3.2. Let robustness be the value's robustness member.
-    const blink::WebMediaKeySystemMediaCapability& capability = capabilities[i];
+    const blink::WebMediaKeySystemMediaCapability& capability =
+        requested_media_capabilities[i];
     // 3.3. If contentType is the empty string, return null.
-    if (capability.mimeType.isEmpty())
+    if (capability.mimeType.isEmpty()) {
+      DVLOG(2) << "Rejecting requested configuration because "
+               << "a capability contentType was empty.";
       return false;
+    }
     // 3.4-3.11. (Implemented by IsSupportedContentType().)
     if (!base::IsStringASCII(capability.mimeType) ||
         !base::IsStringASCII(capability.codecs) ||
@@ -91,26 +194,38 @@ static bool GetSupportedCapabilities(
       continue;
     }
     // 3.12. If robustness is not the empty string, run the following steps:
-    //       (Robustness is not supported.)
-    // TODO(sandersd): Implement robustness. http://crbug.com/442586
     if (!capability.robustness.isEmpty()) {
-      LOG(WARNING) << "Configuration rejected because rubustness strings are "
-                   << "not yet supported.";
-      continue;
+      // 3.12.1. If robustness is an unrecognized value or not supported by
+      //         implementation, continue to the next iteration. String
+      //         comparison is case-sensitive.
+      if (!base::IsStringASCII(capability.robustness))
+        continue;
+      EmeConfigRule robustness_rule = GetRobustnessConfigRule(
+          key_system, media_type, base::UTF16ToASCII(capability.robustness));
+      if (!config_state->IsRuleSupported(robustness_rule))
+        continue;
+      config_state->AddRule(robustness_rule);
+      // 3.12.2. Add robustness to configuration.
+      //         (It's already added, we use capability as configuration.)
     }
     // 3.13. If the user agent and implementation do not support playback of
     //       encrypted media data as specified by configuration, including all
-    //       media types, in combination with accumulated capabilities,
+    //       media types, in combination with local accumulated capabilities,
     //       continue to the next iteration.
-    //       (Skipped as there are no configuration-based codec restrictions.)
-    // 3.14. Add configuration to media type capabilities.
-    media_type_capabilities->push_back(capability);
-    // 3.15. Add configuration to accumulated capabilities.
-    //       (Skipped as there are no configuration-based codec restrictions.)
+    //       (This is handled when adding rules to |config_state|.)
+    // 3.14. Add configuration to supported media capabilities.
+    supported_media_capabilities->push_back(capability);
+    // 3.15. Add configuration to local accumulated capabilities.
+    //       (Skipped as we directly update |config_state|.)
+  }
+  // 4. If supported media capabilities is empty, return null.
+  if (supported_media_capabilities->empty()) {
+    DVLOG(2) << "Rejecting requested configuration because "
+             << "no capabilities were supported.";
+    return false;
   }
-  // 4. If media type capabilities is empty, return null.
   // 5. Return media type capabilities.
-  return !media_type_capabilities->empty();
+  return true;
 }
 
 static EmeFeatureRequirement ConvertRequirement(
@@ -131,15 +246,10 @@ static EmeFeatureRequirement ConvertRequirement(
 static ConfigurationSupport GetSupportedConfiguration(
     const std::string& key_system,
     const blink::WebMediaKeySystemConfiguration& candidate,
-    blink::WebMediaKeySystemConfiguration* accumulated_configuration,
     bool was_permission_requested,
-    bool is_permission_granted) {
-  DCHECK(was_permission_requested || !is_permission_granted);
-
-  // It is possible to obtain user permission unless permission was already
-  // requested and denied.
-  bool is_permission_possible =
-      !was_permission_requested || is_permission_granted;
+    bool is_permission_granted,
+    blink::WebMediaKeySystemConfiguration* accumulated_configuration) {
+  ConfigState config_state(was_permission_requested, is_permission_granted);
 
   // From https://w3c.github.io/encrypted-media/#get-supported-configuration
   // 1. Let accumulated configuration be empty. (Done by caller.)
@@ -184,8 +294,11 @@ static ConfigurationSupport GetSupportedConfiguration(
     }
 
     // 2.3. If supported types is empty, return null.
-    if (supported_types.empty())
+    if (supported_types.empty()) {
+      DVLOG(2) << "Rejecting requested configuration because "
+               << "no initDataType values were supported.";
       return CONFIGURATION_NOT_SUPPORTED;
+    }
 
     // 2.4. Add supported types to accumulated configuration.
     accumulated_configuration->initDataTypes = supported_types;
@@ -200,12 +313,16 @@ static ConfigurationSupport GetSupportedConfiguration(
   //     - "not-allowed": If the implementation requires a Distinctive
   //       Identifier in combination with accumulated configuration, return
   //       null.
-  EmeFeatureRequirement di_requirement =
-      ConvertRequirement(candidate.distinctiveIdentifier);
-  if (!IsDistinctiveIdentifierRequirementSupported(key_system, di_requirement,
-                                                   is_permission_possible)) {
+  // We also reject OPTIONAL when distinctive identifiers are ALWAYS_ENABLED and
+  // permission has already been denied. This would happen anyway at step 11.
+  EmeConfigRule di_rule = GetDistinctiveIdentifierConfigRule(
+      key_system, ConvertRequirement(candidate.distinctiveIdentifier));
+  if (!config_state.IsRuleSupported(di_rule)) {
+    DVLOG(2) << "Rejecting requested configuration because "
+             << "the distinctiveIdentifier requirement was not supported.";
     return CONFIGURATION_NOT_SUPPORTED;
   }
+  config_state.AddRule(di_rule);
 
   // 4. Add the value of the candidate configuration's distinctiveIdentifier
   //    attribute to accumulated configuration.
@@ -219,12 +336,14 @@ static ConfigurationSupport GetSupportedConfiguration(
   //     - "optional": Continue.
   //     - "not-allowed": If the implementation requires persisting state in
   //       combination with accumulated configuration, return null.
-  EmeFeatureRequirement ps_requirement =
-      ConvertRequirement(candidate.persistentState);
-  if (!IsPersistentStateRequirementSupported(key_system, ps_requirement,
-                                             is_permission_possible)) {
+  EmeConfigRule ps_rule = GetPersistentStateConfigRule(
+      key_system, ConvertRequirement(candidate.persistentState));
+  if (!config_state.IsRuleSupported(ps_rule)) {
+    DVLOG(2) << "Rejecting requested configuration because "
+             << "the persistentState requirement was not supported.";
     return CONFIGURATION_NOT_SUPPORTED;
   }
+  config_state.AddRule(ps_rule);
 
   // 6. Add the value of the candidate configuration's persistentState
   //    attribute to accumulated configuration.
@@ -240,7 +359,8 @@ static ConfigurationSupport GetSupportedConfiguration(
     // 7.2. If video capabilities is null, return null.
     std::vector<blink::WebMediaKeySystemMediaCapability> video_capabilities;
     if (!GetSupportedCapabilities(key_system, candidate.videoCapabilities,
-                                  &video_capabilities)) {
+                                  EmeMediaType::VIDEO, &video_capabilities,
+                                  &config_state)) {
       return CONFIGURATION_NOT_SUPPORTED;
     }
 
@@ -258,7 +378,8 @@ static ConfigurationSupport GetSupportedConfiguration(
     // 8.2. If audio capabilities is null, return null.
     std::vector<blink::WebMediaKeySystemMediaCapability> audio_capabilities;
     if (!GetSupportedCapabilities(key_system, candidate.audioCapabilities,
-                                  &audio_capabilities)) {
+                                  EmeMediaType::AUDIO, &audio_capabilities,
+                                  &config_state)) {
       return CONFIGURATION_NOT_SUPPORTED;
     }
 
@@ -274,20 +395,50 @@ static ConfigurationSupport GetSupportedConfiguration(
   //        configuration's distinctiveIdentifier value to "required".
   //      - Otherwise, change accumulated configuration's distinctiveIdentifier
   //        value to "not-allowed".
-  //    (Without robustness support, capabilities do not affect this.)
-  // TODO(sandersd): Implement robustness. http://crbug.com/442586
   if (accumulated_configuration->distinctiveIdentifier ==
       blink::WebMediaKeySystemConfiguration::Requirement::Optional) {
-    if (IsDistinctiveIdentifierRequirementSupported(
-            key_system, EME_FEATURE_NOT_ALLOWED, is_permission_possible)) {
-      accumulated_configuration->distinctiveIdentifier =
-          blink::WebMediaKeySystemConfiguration::Requirement::NotAllowed;
-    } else {
+    EmeConfigRule not_allowed_rule =
+        GetDistinctiveIdentifierConfigRule(key_system, EME_FEATURE_NOT_ALLOWED);
+    EmeConfigRule required_rule =
+        GetDistinctiveIdentifierConfigRule(key_system, EME_FEATURE_REQUIRED);
+    bool not_allowed_supported = config_state.IsRuleSupported(not_allowed_rule);
+    bool required_supported = config_state.IsRuleSupported(required_rule);
+    if (not_allowed_supported) {
+      bool prefer_required = config_state.IsIdentifierRequired() ||
+                             (config_state.IsIdentifierRecommended() &&
+                              config_state.IsPermissionPossible());
+      if (required_supported && prefer_required) {
+        accumulated_configuration->distinctiveIdentifier =
+            blink::WebMediaKeySystemConfiguration::Requirement::Required;
+        config_state.AddRule(required_rule);
+        DCHECK(config_state.IsIdentifierRequired());
+      } else {
+        accumulated_configuration->distinctiveIdentifier =
+            blink::WebMediaKeySystemConfiguration::Requirement::NotAllowed;
+        config_state.AddRule(not_allowed_rule);
+      }
+    } else if (required_supported) {
       accumulated_configuration->distinctiveIdentifier =
           blink::WebMediaKeySystemConfiguration::Requirement::Required;
+      config_state.AddRule(required_rule);
+    } else {
+      // We should not have passed step 3.
+      NOTREACHED();
+      return CONFIGURATION_NOT_SUPPORTED;
     }
   }
 
+  // If permission is required but we couldn't enable it, reject the
+  // configuration.
+  if (config_state.IsIdentifierRequired() &&
+      accumulated_configuration->distinctiveIdentifier !=
+      blink::WebMediaKeySystemConfiguration::Requirement::Required) {
+    DVLOG(2) << "Rejecting requested configuration because "
+             << "distinctiveIdentifier was implicitly required but "
+             << "not allowed.";
+    return CONFIGURATION_NOT_SUPPORTED;
+  }
+
   // 10. If accumulated configuration's persistentState value is "optional",
   //     follow the steps for the first matching condition from the following
   //     list:
@@ -298,59 +449,57 @@ static ConfigurationSupport GetSupportedConfiguration(
   //         to "not-allowed".
   if (accumulated_configuration->persistentState ==
       blink::WebMediaKeySystemConfiguration::Requirement::Optional) {
-    if (IsPersistentStateRequirementSupported(
-            key_system, EME_FEATURE_NOT_ALLOWED, is_permission_possible)) {
+    EmeConfigRule not_allowed_rule =
+        GetPersistentStateConfigRule(key_system, EME_FEATURE_NOT_ALLOWED);
+    EmeConfigRule required_rule =
+        GetPersistentStateConfigRule(key_system, EME_FEATURE_REQUIRED);
+    // Now that distinctiveIdentifier has been resolved, it is too late to allow
+    // persistentState to affect the configuration.
+    bool not_allowed_supported =
+        config_state.IsRuleSupportedWithCurrentState(not_allowed_rule);
+    bool required_supported =
+        config_state.IsRuleSupportedWithCurrentState(required_rule);
+    if (not_allowed_supported) {
       accumulated_configuration->persistentState =
           blink::WebMediaKeySystemConfiguration::Requirement::NotAllowed;
-    } else {
+    } else if (required_supported) {
       accumulated_configuration->persistentState =
           blink::WebMediaKeySystemConfiguration::Requirement::Required;
+    } else {
+      // We should not have passed step 5.
+      NOTREACHED();
+      return CONFIGURATION_NOT_SUPPORTED;
     }
   }
 
   // 11. If implementation in the configuration specified by the combination of
   //     the values in accumulated configuration is not supported or not allowed
   //     in the origin, return null.
-  di_requirement =
-      ConvertRequirement(accumulated_configuration->distinctiveIdentifier);
-  if (!IsDistinctiveIdentifierRequirementSupported(key_system, di_requirement,
-                                                   is_permission_granted)) {
-    if (was_permission_requested) {
-      // The optional permission was requested and denied.
-      // TODO(sandersd): Avoid the need for this logic - crbug.com/460616.
-      DCHECK(candidate.distinctiveIdentifier ==
-             blink::WebMediaKeySystemConfiguration::Requirement::Optional);
-      DCHECK(di_requirement == EME_FEATURE_REQUIRED);
-      DCHECK(!is_permission_granted);
-      accumulated_configuration->distinctiveIdentifier =
-          blink::WebMediaKeySystemConfiguration::Requirement::NotAllowed;
-    } else {
+  // 12. If accumulated configuration's distinctiveIdentifier value is
+  //     "required", [prompt the user for consent].
+  if (accumulated_configuration->distinctiveIdentifier ==
+      blink::WebMediaKeySystemConfiguration::Requirement::Required) {
+    // The caller is responsible for resolving what to do if permission is
+    // required but has been denied (it should treat it as NOT_SUPPORTED).
+    if (!config_state.IsPermissionGranted())
       return CONFIGURATION_REQUIRES_PERMISSION;
-    }
   }
 
-  ps_requirement =
-      ConvertRequirement(accumulated_configuration->persistentState);
-  if (!IsPersistentStateRequirementSupported(key_system, ps_requirement,
-                                             is_permission_granted)) {
-    DCHECK(!was_permission_requested);  // Should have failed at step 5.
-    return CONFIGURATION_REQUIRES_PERMISSION;
-  }
-
-  // 12. Return accumulated configuration.
-  //     (As an extra step, we record the available session types so that
-  //     createSession() can be synchronous.)
+  // 13. Return accumulated configuration.
+  //
+  // We also record the available session types so that createSession() can be
+  // synchronous.
   std::vector<blink::WebEncryptedMediaSessionType> session_types;
   session_types.push_back(blink::WebEncryptedMediaSessionType::Temporary);
   if (accumulated_configuration->persistentState ==
       blink::WebMediaKeySystemConfiguration::Requirement::Required) {
-    if (IsPersistentLicenseSessionSupported(key_system,
-                                            is_permission_granted)) {
+    if (config_state.IsRuleSupportedWithCurrentState(
+            GetPersistentLicenseSessionConfigRule(key_system))) {
       session_types.push_back(
           blink::WebEncryptedMediaSessionType::PersistentLicense);
     }
-    if (IsPersistentReleaseMessageSessionSupported(key_system,
-                                                   is_permission_granted)) {
+    if (config_state.IsRuleSupportedWithCurrentState(
+            GetPersistentReleaseMessageSessionConfigRule(key_system))) {
       session_types.push_back(
           blink::WebEncryptedMediaSessionType::PersistentReleaseMessage);
     }
@@ -474,13 +623,17 @@ void WebEncryptedMediaClientImpl::SelectSupportedConfiguration(
     //        new MediaKeySystemAccess object.]
     blink::WebMediaKeySystemConfiguration accumulated_configuration;
     ConfigurationSupport supported = GetSupportedConfiguration(
-        key_system, candidate_configuration, &accumulated_configuration,
-        was_permission_requested, is_permission_granted);
+        key_system, candidate_configuration, was_permission_requested,
+        is_permission_granted, &accumulated_configuration);
     switch (supported) {
       case CONFIGURATION_NOT_SUPPORTED:
         continue;
       case CONFIGURATION_REQUIRES_PERMISSION:
-        DCHECK(!was_permission_requested);
+        if (was_permission_requested) {
+          DVLOG(2) << "Rejecting requested configuration because "
+                   << "permission was denied.";
+          continue;
+        }
         media_permission_->RequestPermission(
             MediaPermission::PROTECTED_MEDIA_IDENTIFIER,
             GURL(request.securityOrigin().toString()),
diff --git a/media/test/data/eme_player_js/player_utils.js b/media/test/data/eme_player_js/player_utils.js
index d72bef7..86a3e0e 100644
--- a/media/test/data/eme_player_js/player_utils.js
+++ b/media/test/data/eme_player_js/player_utils.js
@@ -85,8 +85,10 @@ PlayerUtils.registerEMEEventListeners = function(player) {
 
   this.registerDefaultEventListeners(player);
   Utils.timeLog('Setting video media keys: ' + player.testConfig.keySystem);
+  var persistentState = player.testConfig.sessionToLoad ? "required"
+                                                        : "optional";
   return navigator.requestMediaKeySystemAccess(
-      player.testConfig.keySystem, [{}])
+      player.testConfig.keySystem, [{persistentState: persistentState}])
       .then(function(access) { return access.createMediaKeys(); })
       .then(function(mediaKeys) {
         return player.video.setMediaKeys(mediaKeys);