[resize-observer-1] Remove ResizeObservation from IDL index

Author: saschanaz

resize-observer-1/Overview.bs

@@ -305,7 +305,7 @@ A future version of this spec will extend the returned {{FrozenArray}} to contai
 included here in order to help provide clarity during the processing model. It effectively holds observation information for a single {{Element}}. This
 interface is not visible to Javascript.</p>
 
-<pre class="idl exclude">
+<pre class="idl extract">
 interface ResizeObservation {
     constructor(Element target);
     readonly attribute Element target;
@@ -530,15 +530,15 @@ elements do not use standard CSS box model.
 To <dfn>calculate box size</dfn>, given |target| and |observedBox|, run these steps:
 
     1. If |target| is an {{SVGGraphicsElement}}
-    
+
         1. If |observedBox| is "border-box" or "content-box"
 
             1. Set |computedSize|.inlineSize to |target|'s <a>bounding box</a> inline length.
 
             2. Set |computedSize|.blockSize to |target|'s <a>bounding box</a> block length.
-        
+
         2. 1. If |observedBox| is "device-pixel-content-box"
-        
+
             1. Set |computedSize|.inlineSize to |target|'s <a>bounding box</a> inline length, in integral device pixels.
 
             2. Set |computedSize|.blockSize to |target|'s <a>bounding box</a> block length, in integral device pixels.