Merge pull request #2617 from mjwilson-google/current-time

Revise wording for currentTime

Author: mjwilson-google

index.bs

@@ -10534,10 +10534,9 @@ Attributes</h5>
 
     : <dfn>currentTime</dfn>
     ::
-        The context time of the block of audio being processed. By
-        definition this will be equal to the value of
-        {{BaseAudioContext}}'s {{BaseAudioContext/currentTime}} attribute that was most
-        recently observable in the <a>control thread</a>.
+        The context time of the block of audio being processed. This must be
+        equal to the value of {{BaseAudioContext}}'s
+        {{BaseAudioContext/currentTime}} attribute.
 
     : <dfn>sampleRate</dfn>
     ::