Add a function to convert key system into UUID

media/base/android/media_drm_bridge.h

 // Copyright (c) 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 MEDIA_BASE_ANDROID_MEDIA_DRM_BRIDGE_H_
 #define MEDIA_BASE_ANDROID_MEDIA_DRM_BRIDGE_H_
 
 #include <jni.h>
 #include <string>
 #include <vector>
 
 #include "base/android/scoped_java_ref.h"
 #include "media/base/media_export.h"
 #include "media/base/media_keys.h"
 
 namespace media {
 
 // This class provides DRM services for android EME implementation.
 // TODO(qinmin): implement all the functions in this class.
 class MEDIA_EXPORT MediaDrmBridge : public MediaKeys {
  public:
-  // TODO(xhwang): Pass in |key_system|.
-  MediaDrmBridge(int media_keys_id, const std::vector<uint8>& uuid);
   virtual ~MediaDrmBridge();
 
+  // Returns a MediaDrmBridge instance if |uuid| is supported, or a NULL
+  // pointer otherwise.
+  static MediaDrmBridge* Create(int media_keys_id,
+                                const std::vector<uint8>& uuid);
+
   // Checks whether DRM is available.
   static bool IsAvailable();
 
   // MediaKeys implementations.
   virtual bool GenerateKeyRequest(const std::string& type,
                                   const uint8* init_data,
                                   int init_data_length) OVERRIDE;
   virtual void AddKey(const uint8* key, int key_length,
                       const uint8* init_data, int init_data_length,
                       const std::string& session_id) OVERRIDE;
   virtual void CancelKeyRequest(const std::string& session_id) OVERRIDE;
 
   // Drm related message was received.
   void OnDrmEvent(JNIEnv* env, jobject, jstring session_id,
                   jint event, jint extra, jstring data);
 
   // Called after we got the response for GenerateKeyRequest().
   void OnKeyMessage(JNIEnv* env, jobject, jstring session_id,
                     jbyteArray message, jstring destination_url);
 
   // Methods to create and release a MediaCrypto object.
   base::android::ScopedJavaLocalRef<jobject> CreateMediaCrypto(
       const std::string& session_id);
   void ReleaseMediaCrypto(const std::string& session_id);
 
   int media_keys_id() const { return media_keys_id_; }
 
  private:
+  MediaDrmBridge(int media_keys_id, const std::vector<uint8>& uuid);
+
   // Id of the MediaKeys object.
   int media_keys_id_;
 
+  // UUID of the key system.
+  std::vector<uint8> uuid_;
+
   DISALLOW_COPY_AND_ASSIGN(MediaDrmBridge);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_ANDROID_MEDIA_DRM_BRIDGE_H_