非标准
该特性是非标准的，请尽量不要在生产环境中使用它！
The IdentityManager of the BrowserID protocol exposes the BrowserID API, via navigator.id. This API has gone through several significant revisions. Each generation is listed separately below.
The "Observer" API (Current)
The Observer API introduces much-requested features, such as an improved post-verification experience for first-time users, automatic persistent logins, and easier integration with native applications.
IdentityManager.watch()- Registers callbacks to be invoked when a user logs into or out of a website.
IdentityManager.request()- Requests a signed identity assertion from the user.
IdentityManager.logout()- Logs the user out of a website and prevents the
onloginaction from automatically firing on their next visit.
Users with third-party cookies disabled may experience problems logging in using the Observer API as detailed in issue 2999.
The "Callback" API (Current)
The Callback API was introduced in November 2011. It improved upon the initial API by allowing options to be passed to navigator.id.get() and offering experimental support for BrowserID-managed persistent sessions.
IdentityManager.get()- Gets the user's BrowserID in a signed assertion.
The "VerifiedEmail" API (Deprecated)
The VerifiedEmail API was BrowserID's first API. It was deprecated at the end of 2011.
IdentityManager.getVerifiedEmail()- Gets the user's BrowserID in a signed assertion. This method is deprecated;
navigator.id.get()is backwards compatible and can be used instead.