Remove unused 'current time' definition (#295)

Closes #235

Author: noamr

index.html

@@ -251,11 +251,6 @@ <h2>
         "NAVIGATION-TIMING-2#dom-PerformanceNavigationTiming-startTime">start
         of navigation of the document</a> occurs at time 0.
       </p>
-      <p>
-        The term <dfn>current time</dfn> refers to the number of milliseconds
-        since the start of navigation of the document until the current moment
-        in time.
-      </p>
       <p class='note'>
         This definition of time is based on the High Resolution Time
         specification [[HR-TIME-2]] and is different from the definition of