media: Add UMA and trace events for CDM creation.

media/blink/cdm_session_adapter.h

 // Copyright 2014 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_BLINK_CDM_SESSION_ADAPTER_H_
 #define MEDIA_BLINK_CDM_SESSION_ADAPTER_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 92 matching lines @@
 
   // Session ID to WebContentDecryptionModuleSessionImpl mapping.
   typedef base::hash_map<std::string,
                          base::WeakPtr<WebContentDecryptionModuleSessionImpl> >
       SessionMap;
 
   ~CdmSessionAdapter();
 
   // Callback for CreateCdm().
   void OnCdmCreated(const std::string& key_system,
+                    base::TimeTicks start_time,
                     blink::WebContentDecryptionModuleResult result,
                     scoped_ptr<MediaKeys> cdm,
                     const std::string& error_message);
 
   // Callbacks for firing session events.
   void OnSessionMessage(const std::string& session_id,
                         MediaKeys::MessageType message_type,
                         const std::vector<uint8_t>& message,
                         const GURL& legacy_destination_url);
   void OnSessionKeysChange(const std::string& session_id,
                            bool has_additional_usable_key,
                            CdmKeysInfo keys_info);
   void OnSessionExpirationUpdate(const std::string& session_id,
                                  const base::Time& new_expiry_time);
   void OnSessionClosed(const std::string& session_id);
   void OnLegacySessionError(const std::string& session_id,
                             MediaKeys::Exception exception_code,
                             uint32_t system_code,
                             const std::string& error_message);
 
   // Helper function of the callbacks.
   WebContentDecryptionModuleSessionImpl* GetSession(
       const std::string& session_id);
 
+  void ReportTimeToCreateCdmUMA(base::TimeDelta cdm_creation_time) const;
+
   scoped_ptr<MediaKeys> cdm_;
 
   SessionMap sessions_;
 
   std::string key_system_;
   std::string key_system_uma_prefix_;
 
+  // A unique ID to trace CdmSessionAdapter::CreateCdm() call and the matching
+  // OnCdmCreated() call.
+  uint32 trace_id_;
+
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<CdmSessionAdapter> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CdmSessionAdapter);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BLINK_CDM_SESSION_ADAPTER_H_