Fix a bunch of UI nits in sheriff-o-matic.

Tools/GardeningServer/ui/ct-results-panel.html

 <!--
 Copyright 2014 The Chromium Authors. All rights reserved.
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 -->
 
 <link rel="import" href="../bower_components/core-menu/core-menu.html">
 <link rel="import" href="../bower_components/paper-item/paper-item.html">
 <link rel="import" href="ct-results-by-builder.html">
 <link rel="import" href="ct-embedded-flakiness-dashboard.html">
 
 <polymer-element name="ct-results-panel" attributes="failures">
   <template>
     <style>
       :host {
-        display: block;
+        display: flex;
+        flex-direction: column;
       }
 
       paper-item.core-selected {
         font-weight: bold;
       }
 
       .message {
+        margin: 20px;
         text-align: center;
-        margin: 20px;
+      }
+
+      core-menu {
+        box-shadow: 0 3px 3px #ccc;
+        /* Override /deep/ selector in core-menu.css. */
+        margin: 0 !important;
+        max-height: 20%;
+        min-height: 150px;
+        overflow: auto;
+        /* So the box-shadow goes on top of the results. */
+        z-index: 1;
+      }
+
+      .results {
+        /* Stay below the box shadow of the core-menu. */
+        padding-top: 6px;
+        flex: 1;
+        overflow: auto;
       }
     </style>
-    <template if="{{!failures.length}}">
+    <template if="{{ !failures.length }}">
       <div class="message">No results to display.</div>
     </template>
-    <template if="{{failures.length}}">
-      <core-menu selected="{{selected}}">
-        <template repeat="{{failure in failures}}">
-          <paper-item label="{{failure.testName}}"></paper-item>
+    <template if="{{ failures.length }}">
+      <core-menu selected="{{ selected }}">
+        <template repeat="{{ failure in failures }}">
+          <paper-item label="{{ failure.testName }}"></paper-item>
         </template>
       </core-menu>
-      <ct-embedded-flakiness-dashboard test="{{failures[selected].testName}}"></ct-embedded-flakiness-dashboard>
-      <ct-results-by-builder failure="{{failures[selected]}}"></ct-results-by-builder>
+      <div class="results">
+        <ct-embedded-flakiness-dashboard test="{{ failures[selected].testName }}"></ct-embedded-flakiness-dashboard>
+        <ct-results-by-builder failure="{{ failures[selected] }}"></ct-results-by-builder>
+      </div>
     </template>
   </template>
   <script>
     Polymer({
       failures: [],
       selected: 0,
 
       failuresChanged: function() {
         this.selected = 0;
       },
     });
   </script>
 </polymer-element>