Add Promises for EME (Chromium side)

content/renderer/media/webcontentdecryptionmodulesession_impl.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_RENDERER_MEDIA_WEBCONTENTDECRYPTIONMODULESESSION_IMPL_H_
 #define CONTENT_RENDERER_MEDIA_WEBCONTENTDECRYPTIONMODULESESSION_IMPL_H_
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "media/base/media_keys.h"
 #include "third_party/WebKit/public/platform/WebContentDecryptionModuleSession.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 
 namespace media {
 class MediaKeys;
 }
 
 namespace content {
 class CdmSessionAdapter;
 
 class WebContentDecryptionModuleSessionImpl
     : public blink::WebContentDecryptionModuleSession {
  public:
   WebContentDecryptionModuleSessionImpl(
-      uint32 session_id,
       Client* client,
       const scoped_refptr<CdmSessionAdapter>& adapter);
   virtual ~WebContentDecryptionModuleSessionImpl();
 
   // blink::WebContentDecryptionModuleSession implementation.
   virtual blink::WebString sessionId() const;
   virtual void initializeNewSession(const blink::WebString& mime_type,
                                     const uint8* init_data,
                                     size_t init_data_length);
   virtual void update(const uint8* response, size_t response_length);
   virtual void release();
 
   // Callbacks.
-  void OnSessionCreated(const std::string& web_session_id);
   void OnSessionMessage(const std::vector<uint8>& message,
                         const GURL& destination_url);
   void OnSessionReady();
   void OnSessionClosed();
-  void OnSessionError(media::MediaKeys::KeyError error_code,
-                      uint32 system_code);
+  void OnSessionError(media::MediaKeys::Exception exception_code,
+                      uint32 system_code,
+                      const std::string& error_message);
 
  private:
+  void SessionCreated(const std::string& web_session_id);
+
   scoped_refptr<CdmSessionAdapter> adapter_;
 
   // Non-owned pointer.
   Client* client_;
 
   // Web session ID is the app visible ID for this session generated by the CDM.
-  // This value is not set until the CDM calls OnSessionCreated().
-  blink::WebString web_session_id_;
+  // This value is not set until the CDM resolves the initializeNewSession()
+  // promise.
+  std::string web_session_id_;
 
-  // Session ID is used to uniquely track this object so that CDM callbacks
-  // can get routed to the correct object.
-  const uint32 session_id_;
+  // Since promises will live until they are fired, use a weak reference when
+  // creating a promise in case this class disappears before the promise
+  // actually fires.
+  base::WeakPtrFactory<WebContentDecryptionModuleSessionImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentDecryptionModuleSessionImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_WEBCONTENTDECRYPTIONMODULESESSION_IMPL_H_