百度 卸妆效果测试菲诗小铺迷雾唇膏笔卸妆效果评测方法：再用化妆棉蘸取卸妆水擦拭涂有唇膏笔的肌肤，通过观察唇膏的残留情况，以评测菲诗小铺唇膏笔的卸妆效果。

Media Session manages the media session and audio focus for playback across the entire system.

Clients can use the Audio Focus API to request audio focus and observe changes through AudioFocusObserver. The Media Session API can be used to control playback and observe changes through MediaSessionObserver.

For more details about controlling playback see controlling Media Playback.

TODO(beccahughes): Write docs about requesting audio focus.

Media Session IDs

The Media Session service uses base::UnguessableToken for a number of different reasons, these are:

• Request IDs: These identify a single media session
• Group IDs: These group together a number of media sessions that should share focus, this is usually per-app.
• Source IDs: These identity a user/profile that created a media session

Every media session has its own unique request ID and it may also have a group ID and a source ID.