Fix resize demo (and sample code) to work with new scrolling approach

demo/resize.html

@@ -15,7 +15,6 @@
         height: auto;
         overflow-y: hidden;
         overflow-x: auto;
-        width: 100%;
       }
     </style>
   </head>
@@ -27,7 +26,6 @@
   height: auto;
   overflow-y: hidden;
   overflow-x: auto;
-  width: 100%
 }</textarea></form>
 
 <p>By setting a few CSS properties, CodeMirror can be made to