[Debugger Plugin] Remove "Refresh" Button from Value Cards (#1017)

Instead, bind the refresh() method to on-change events of the Slicing and Time Indices input boxes.

Author: caisq

tensorboard/plugins/debugger/tf_debugger_dashboard/tf-tensor-value-view.html

@@ -67,25 +67,23 @@
               class="inline value-card-input"
               label="Slicing"
               id="slicing"
-              value="{{slicing}}">
+              value="{{slicing}}"
+              on-change="refresh">
             </paper-input>
           </div>
           <div>
             <paper-input
               class="inline value-card-input"
               label="Time Indices"
               id="time-indices"
-              value="{{timeIndices}}">
+              value="{{timeIndices}}"
+              on-change="refresh">
             </paper-input>
             <paper-button raised
               id='time-indices-toggle-button'
               class='tensor-value-buttons'
               on-click='_timeIndicesToggleButtonCallback'
             >Full History</paper-button>
-            <paper-button raised
-              class="tensor-value-buttons"
-              on-click="refresh"
-            >Refresh</paper-button>
           </div>
         </td>
         <td class="tensor-value-view-td">