【fix】 classic 示例缺陷。

Author: tangqinGiser

examples/classic/map_overlayLayer.html

@@ -7,6 +7,20 @@
     <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
     <title data-i18n="resources.title_overlayLayer"></title>
     <style type="text/css">
+        body {
+            margin: 0;
+            overflow: hidden;
+            background: #fff;
+            width: 100%;
+            height: 100%
+        }
+
+        #map {
+            position: absolute;
+            width: 100%;
+            height: 100%;
+            border: 1px solid #3473b7;
+        }
         .editPane {
             position: absolute;
             right: 10px;