Rework how types work in the VM Service.

runtime/bin/vmservice/observatory/lib/src/elements/instance_ref.html

 <link rel="import" href="../../../../packages/polymer/polymer.html">
 <link rel="import" href="curly_block.html">
 <link rel="import" href="observatory_element.html">
 <link rel="import" href="service_ref.html">
 
 <polymer-element name="instance-ref" extends="service-ref">
   <template>
     <link rel="stylesheet" href="css/shared.css">
     <style>
       .errorBox {
         background-color: #f5f5f5;
         border: 1px solid #ccc;
         padding: 10px;
         font-family: consolas, courier, monospace;
         font-size: 1em;
         line-height: 1.2em;
         white-space: pre;
       }
     </style>
     <span>
       <template if="{{ ref.isSentinel }}">
         <div title="{{ hoverText }}">{{ ref.valueAsString }}</div>
       </template>
 
-      <template if="{{ ref.isString || ref.isBool || ref.isInt || ref.isDouble || ref.isNull }}">
+      <template if="{{ ref.isString || ref.isBool || ref.isInt ||
+                       ref.isDouble || ref.isNull }}">
         <a on-click="{{ goto }}" _href="{{ url }}">{{ ref.valueAsString }}</a>
       </template>
 
-      <template if="{{ ref.isType }}">
+      <template if="{{ ref.isAbstractType }}">
         <a on-click="{{ goto }}" _href="{{ url }}">{{ ref.name }}</a>
       </template>
 
       <template if="{{ ref.isClosure }}">
         <a on-click="{{ goto }}" _href="{{ url }}">
           <!-- TODO(turnidge): Switch this to fully-qualified function -->
           {{ ref.closureFunc.name }}
         </a>
       </template>
 
-      <template if="{{ ref.isInstance && !ref.isClosure }}">
+      <template if="{{ ref.isPlainInstance }}">
         <a on-click="{{ goto }}" _href="{{ url }}"><em>{{ ref.clazz.name }}</em></a>
         <curly-block callback="{{ expander() }}">
           <div class="memberList">
             <template repeat="{{ field in ref.fields }}">
               <div class="memberItem">
                 <div class="memberName">
                   {{ field['decl'].name }}
                 </div>
                 <div class="memberValue">
                   <any-service-ref ref="{{ field['value'] }}"></any-service-ref>
@@ skipping 51 matching lines @@
               </div>
             </div>
           </div>
         </curly-block>
       </template>
     </span>
   </template>
 </polymer-element>
 
 <script type="application/dart" src="instance_ref.dart"></script>