[dailymotion] Extract duration (closes #6221)

youtube_dl/extractor/dailymotion.py

@@ -53,6 +53,7 @@ class DailymotionIE(DailymotionBaseInfoExtractor):
                 'uploader': 'IGN',
                 'title': 'Steam Machine Models, Pricing Listed on Steam Store - IGN News',
                 'upload_date': '20150306',
+                'duration': 74,
             }
         },
         # Vevo video
@@ -164,6 +165,7 @@ class DailymotionIE(DailymotionBaseInfoExtractor):
             'thumbnail': info['thumbnail_url'],
             'age_limit': age_limit,
             'view_count': view_count,
+            'duration': info['duration']
         }
 
     def _get_subtitles(self, video_id, webpage):