[web-animations-1] Make order of applying pending playback rate and updating start time more consistent

This is just a tweak to make sure that *most* of the time we apply the
pending playback rate first. This doesn't have any observable effects
but provides a little added consistency.

Author: birtles

web-animations-1/Overview.bs

@@ -915,8 +915,8 @@ The procedure to <dfn>set the current time</dfn> of an animation,
 1.  If <var>animation</var> has a <a>pending pause task</a>, synchronously
     complete the pause operation by performing the following steps:
     1.  Set <var>animation</var>'s <a>hold time</a> to <var>seek time</var>.
-    1.  Make <var>animation</var>'s [=start time=] <a>unresolved</a>.
     1.  [=Apply any pending playback rate=] to |animation|.
+    1.  Make <var>animation</var>'s [=start time=] <a>unresolved</a>.
     1.  Cancel the <a>pending pause task</a>.
     1.  <a lt="resolve a Promise">Resolve</a> <var>animation</var>'s
         <a>current ready promise</a> with <var>animation</var>.
@@ -953,10 +953,10 @@ is as follows:
     previous step which may cause the <a>current time</a> to become
     <a>unresolved</a>.
 
-1.  Set <var>animation</var>'s [=start time=] to <var>new start time</var>.
-
 1.  [=Apply any pending playback rate=] on |animation|.
 
+1.  Set <var>animation</var>'s [=start time=] to <var>new start time</var>.
+
 1.  Update <var>animation</var>'s <a>hold time</a> based on the first matching
     condition from the following,