[css-snappoints] Removing box argument to scroll-snap-area value per working group resolution that I had forgotten about *facepalm* https://lists.w3.org/Archives/Public/www-style/2015Nov/0306.html

Author: ChumpChief

css-snappoints/Overview.bs

@@ -189,7 +189,7 @@ Ignored Terms: scroll-snap-positions-*, containing block chain
 
         <dt><dfn lt="scroll snap area" local-lt="snap area" export>snap area</dfn>
         <dd>
-            An element's snap area is the rectangle obtained by expanding its specified box by its 'scroll-snap-area'.
+            An element's snap area is the rectangle obtained by expanding its border box by its 'scroll-snap-area'.
 
         <dt><dfn lt="scroll snap position" local-lt="snap position" export>snap position</dfn>
         <dd>
@@ -264,20 +264,20 @@ Ignored Terms: scroll-snap-positions-*, containing block chain
 
     <pre class="propdef">
     Name: scroll-snap-area
-    Value: [ border-box | margin-box ]? [ <<length>> | <<percentage>> ]{1,4}
+    Value: [ <<length>> | <<percentage>> ]{1,4}
     Initial: 0
     Applies to: all elements
     Inherited: no
-    Percentages: relative to the specified element box
+    Percentages: relative to the border box
     Media: interactive
     Computed value: as specified, with lengths made absolute
     Animatable: yes
     </pre>
 
     <dl dfn-type=value dfn-for="scroll-snap-area">
-        <dt><dfn>[ border-box | margin-box ]? [ <<length>> | <<percentage>> ]{1,4}</dfn>
+        <dt><dfn>[ <<length>> | <<percentage>> ]{1,4}</dfn>
         <dd>
-            Specifies the outset of the element's snap area from the axis-aligned bounding box of the transformed specified box, in the <a>scroll container's</a> coordinate space.  Outsets are applied to this bounding box, not the specified box.  If the box argument is omitted it defaults to border-box.
+            Specifies the outset of the element's snap area from the axis-aligned bounding box of the transformed border box, in the <a>scroll container's</a> coordinate space.  Outsets are applied to this bounding box, not the border box.
 
             Note: This ensures that the <a>scroll snap area</a> is always rectangular and axis-aligned to the <a>scroll container's</a> coordinate space.
     </dl>