Adding back in condition for current phase that is needed when animation is in idle state

Author: Jordan Taylor

web-animations-1/Overview.bs

@@ -951,7 +951,11 @@ below:
 :   If the animation's <a>hold phase</a> is set,
 ::  The <a>current phase</a> is the animation's <a>hold phase</a>.
 
-:   If the animation has no associated <a>timeline</a>:
+:   If <em>either</em> of the following are true:
+
+    1.  the animation has no associated <a>timeline</a>, or
+    1.  the animation's [=start time=] is <a>unresolved</a>.
+
 ::  The <a>current phase</a> is [=timeline inactive phase|inactive=].
 
 :   Otherwise,