Make local variables sticky-scroll in debugger frames.

runtime/observatory/lib/src/elements/debugger.html

Index: runtime/observatory/lib/src/elements/debugger.html
diff --git a/runtime/observatory/lib/src/elements/debugger.html b/runtime/observatory/lib/src/elements/debugger.html
index 570f19575d95b94480896688aa62e5a1e8d34173..20e2e4d649cd7c814e1fde34c55e8c2d6552313b 100644
--- a/runtime/observatory/lib/src/elements/debugger.html
+++ b/runtime/observatory/lib/src/elements/debugger.html
@@ -238,6 +238,12 @@
         flex-basis: 250px;
         overflow-x: hidden;
       }
+      #vars {
+        position: relative;
+        top: 5px;
+        padding-left:2em;
+        padding-bottom: 5px;
+      }
     </style>
     <div id="frameOuter" class="frameOuter">
       <a on-click="{{ toggleExpand }}">
@@ -268,7 +274,7 @@
               </source-inset>
             </div>
             <div class="flex-item-vars">
-              <div style="padding-left:2em;" class="memberList">
+              <div id="vars" class="memberList">
                 <template repeat="{{ v in properLocals }}">
                   {{ v['name']}}&nbsp;:&nbsp;
                   <any-service-ref ref="{{ v['value'] }}"