MD Downloads: use computed data binding to hide removal (X)

chrome/browser/resources/md_downloads/item.html

 <link rel="import" href="chrome://resources/html/action_link.html">
 <link rel="import" href="chrome://resources/html/cr.html">
 <link rel="import" href="chrome://resources/html/load_time_data.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/polymer/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-material/paper-material.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-progress/paper-progress.html">
 <link rel="import" href="chrome://downloads/action_service.html">
 <link rel="import" href="chrome://downloads/constants.html">
 <link rel="import" href="chrome://downloads/throttled_icon_loader.html">
@@ skipping 67 matching lines @@
           <!-- Things that safe browsing has determined to be dangerous. -->
           <template is="dom-if" if="[[isMalware_]]">
             <paper-button id="danger-remove" on-click="onDiscardDangerous_"
                 class="discard">[[i18n_.remove]]</paper-button>
             <paper-button id="restore" on-click="onSaveDangerous_"
                 class="keep">[[i18n_.restore]</paper-button>
           </template>
         </div>
       </div>
 
       <div id="remove-wrapper" class="icon-wrapper">

[tommycli, 2015/09/08 22:45:19]

I assume you want to leave a 'space' visually for it rather than deleting the
node entirely?

[Dan Beam, 2015/09/08 23:07:35]

Yes

         <paper-icon-button id="remove" icon="clear"
+            style$="[[computeRemoveStyle_(isDangerous_, showCancel_)]]"

[tommycli, 2015/09/08 22:45:19]

This is called with two parameters, but the Javascript defines a parameterless
function.

[Dan Beam, 2015/09/08 23:07:35]

these also act as dependencies as well (e.g. if isDangerous_ or showCancel_
change: call this function)

             on-click="onRemoveClick_"></paper-icon-button>
       </div>
 
       <div id="incognito" hidden$="[[!data_.otr]]"></div>
     </paper-material>
 
     <div id="end-cap"></div>
 
   </template>
   <link rel="import" type="css" href="chrome://resources/css/action_link.css">
   <link rel="import" type="css" href="chrome://downloads/shared_style.css">
   <link rel="import" type="css" href="chrome://downloads/item.css">
   <script src="chrome://downloads/item.js"></script>
 </dom-module>