Implement robustness strings in requestMediaKeySystemAccess().

media/base/eme_constants.h

Index: media/base/eme_constants.h
diff --git a/media/base/eme_constants.h b/media/base/eme_constants.h
index 4462c5cc0b251686c30bb1ef99b5a716248d7710..b48309cef0e31a9aff8edd6df43596e409925837 100644
--- a/media/base/eme_constants.h
+++ b/media/base/eme_constants.h
@@ -54,32 +54,75 @@ 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,
+};
+

[lcwu1, 2015/03/24 00:19:49]

Just chatted with ddorwin@ off-line. I felt that this enum should be in
Widevine-specific code instead of here in eme_constants.h. (David provide some
rationals for doing it this way. I will let him respond with his answers.)

[ddorwin, 2015/03/24 00:24:37]

I was just saying that we would have to pass strings around and convert them
repeatedly, whereas today the conversion happens once at the higher levels. It's
possible things will change when KeySystems is refactored (issue 457438). It's
also possible that other systems would map onto a common set of levels.

[ddorwin, 2015/03/24 18:00:27]

If refactoring does not address this, we probably need to move
ConvertRobustness() into Key Systems so that we don't have key system-specific
strings in webencryptedmediaclient_impl.cc.

For now, this CL is a step forward in spec compliance in Chrome. Support for
other robustness level-supporting key systems may require additional changes.

+// 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_