Add UMA reporting to CdmPromise.

media/base/media_keys.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 MEDIA_BASE_MEDIA_KEYS_H_
 #define MEDIA_BASE_MEDIA_KEYS_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 36 matching lines @@
   };
 
   // Must be a superset of cdm::MediaKeyException.
   enum Exception {
     NOT_SUPPORTED_ERROR,
     INVALID_STATE_ERROR,
     INVALID_ACCESS_ERROR,
     QUOTA_EXCEEDED_ERROR,
     UNKNOWN_ERROR,
     CLIENT_ERROR,
-    OUTPUT_ERROR
+    OUTPUT_ERROR,
+    NUM_EXCEPTIONS  // Insert new exceptions before this.
   };
 
   // Type of license required when creating/loading a session.
   // Must be consistent with the values specified in the spec:
   // https://dvcs.w3.org/hg/html-media/raw-file/default/encrypted-media/encrypted-media.html#extensions
   enum SessionType {
     TEMPORARY_SESSION,
     PERSISTENT_SESSION
   };
 
@@ skipping 48 matching lines @@
 typedef base::Callback<void(const std::string& web_session_id)> SessionClosedCB;
 
 typedef base::Callback<void(const std::string& web_session_id,
                             MediaKeys::Exception exception_code,
                             uint32 system_code,
                             const std::string& error_message)> SessionErrorCB;
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_MEDIA_KEYS_H_