Implement checks for distinctiveIdentifier and persistentState in requestMediaKeySystemAccess().

media/base/key_systems.h

Index: media/base/key_systems.h
diff --git a/media/base/key_systems.h b/media/base/key_systems.h
index d761abf2c66a3cc1391754588b1a71bfce2b43cc..10bee2fba73157abead771394148860ee2c912f5 100644
--- a/media/base/key_systems.h
+++ b/media/base/key_systems.h
@@ -9,6 +9,7 @@
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
+#include "media/base/eme_constants.h"
 #include "media/base/media_export.h"
 
 namespace media {
@@ -78,6 +79,23 @@ MEDIA_EXPORT std::string GetPepperType(
     const std::string& concrete_key_system);
 #endif
 
+// Returns whether |key_system| supports the specified distinctive identifier
+// requirement.
+MEDIA_EXPORT bool IsSupportedDistinctiveIdentifierRequirement(

[ddorwin, 2015/02/17 22:34:58]

We may need to pass more information (is authorized), track this in an object,
or return more states (i.e. yes, now, if authorized).

[sandersd (OOO until July 31), 2015/02/18 23:41:18]

That's true. I was hoping to skip that for this CL, as it doesn't affect the
logic we are implementing quite yet.

+    const std::string& key_system,
+    EmeRequirement requirement);

[ddorwin, 2015/02/17 22:34:58]

In this case, we are passing the requirement from the app. We could do the
conversion inside these functions.

[sandersd (OOO until July 31), 2015/02/18 23:41:18]

I've left the conversion outside to avoid infecting KeySystems with knowledge of
Blink.

+
+// Returns whether |key_system| supports the specified persistent state
+// requirement.
+MEDIA_EXPORT bool IsSupportedPersistentStateRequirement(
+    const std::string& key_system,
+    EmeRequirement requirement);
+
+// Returns whether |key_system| supports the specified session type.
+MEDIA_EXPORT bool IsSupportedSessionType(
+    const std::string& key_system,
+    EmeSessionType session_type);
+
 #if defined(UNIT_TEST)
 // Helper functions to add container/codec types for testing purposes.
 MEDIA_EXPORT void AddContainerMask(const std::string& container, uint32 mask);