Implement Chromium side of MediaKeys.isTypeSupported().

content/public/renderer/key_system_info.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_PUBLIC_RENDERER_KEY_SYSTEM_INFO_H_
 #define CONTENT_PUBLIC_RENDERER_KEY_SYSTEM_INFO_H_
 
 #include <map>
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/containers/hash_tables.h"
 #include "content/common/content_export.h"
 #include "content/public/common/eme_codec.h"
+#include "content/public/common/eme_init_data_type.h"
 
 // Definitions:
 // * Key system
 //    https://dvcs.w3.org/hg/html-media/raw-file/default/encrypted-media/encrypted-media.html#key-system
 // * Concrete key system
 //    A key system string that can be instantiated, such as
 //    via the MediaKeys constructor. Examples include "org.w3.clearkey" and
 //    "com.widevine.alpha".
 // * Abstract key system
 //    A key system string that cannot be instantiated like a concrete key system
 //    but is otherwise useful, such as in discovery using isTypeSupported().
 // * Parent key system
 //    A key system string that is one level up from the child key system. It may
 //    be an abstract key system.
 //    As an example, "com.example" is the parent of "com.example.foo".
 
 namespace content {
 
 // Contains information about an EME key system as well as how to instantiate
 // the corresponding CDM.
 struct CONTENT_EXPORT KeySystemInfo {
   explicit KeySystemInfo(const std::string& key_system);
   ~KeySystemInfo();
 
   std::string key_system;
 
   // Specifies codecs supported by |key_system|.
   SupportedCodecs supported_codecs;
 
+  // Specifies registered initialization data types supported by |key_system|.
+  SupportedInitDataTypes supported_init_data_types;
+
   // A hierarchical parent for |key_system|. This value can be used to check
   // supported types but cannot be used to instantiate a MediaKeys object.
   // Only one parent key system is currently supported per concrete key system.
   std::string parent_key_system;
 
   // The following indicate how the corresponding CDM should be instantiated.
   bool use_aes_decryptor;
 #if defined(ENABLE_PEPPER_CDMS)
   std::string pepper_type;
 #endif
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_RENDERER_KEY_SYSTEM_INFO_H_