Use WHATWG/INFRA 'is' definition for 'match'

[himorin]

In step 2., spec states

Otherwise, if mark is a DOMString, let end time be the value of the startTime attribute from the most recent occurrence of a PerformanceMark object in the performance entry buffer whose name matches the value of mark. If no matching entry is found, throw a SyntaxError.

which uses a text whose name matches the value of mark over user defined DOMString value. To use clear state, this text could refer is in WHATWG/INFRA instead of just matches. (also there is no clear definition of match in this spec.)

[npm1]

Sure, we can change matches to is (PR welcome, or I'll create one next week)