PerformanceEntry object encapsulates a single performance metric that is part of the performance timeline. A performance entry can be directly created by making a performance
measure (for example by calling the
mark() method) at an explicit point in an application. Performance entries are also created in indirect ways such as loading a resource (such as an image).
DOMHighResTimeStamp representing the time value of the duration of the performance event.
DOMString representing the type of performance metric such as, for example, "
mark". See property page for valid values.
A value that further specifies the value returned by the
PerformanceEntry.entryType property. The value of both depends on the subtype. See property page for valid values.