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

chrome/browser/resources/md_downloads/item.js

 // Copyright 2015 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.
 
 cr.define('downloads', function() {
   var Item = Polymer({
     is: 'downloads-item',
 
     /**
      * @param {!downloads.ThrottledIconLoader} iconLoader
@@ skipping 140 matching lines @@
       this.$.content.classList.toggle('dangerous', this.isDangerous_);
 
       var description = this.getDangerText_(data) || this.getStatusText_(data);
 
       // Status goes in the "tag" (next to the file name) if there's no file.
       this.ensureTextIs_(this.$.description, isActive ? description : '');
       this.ensureTextIs_(this.$.tag, isActive ? '' : description);
 
       this.$.content.classList.toggle('show-progress', this.showProgress_);
 
-      var hideRemove;
-
-      if (this.isDangerous_) {
-        hideRemove = true;
-      } else {
+      if (!this.isDangerous_) {
         this.$['file-link'].href = data.url;
         this.ensureTextIs_(this.$['file-link'], data.file_name);
 
         this.$['file-link'].hidden = !this.completelyOnDisk_;
         this.$.name.hidden = this.completelyOnDisk_;
 
-        hideRemove = this.showCancel_ ||
-            !loadTimeData.getBoolean('allowDeletingHistory');
-
         /** @const */ var controlledByExtension = data.by_ext_id &&
                                                   data.by_ext_name;
         this.$['controlled-by'].hidden = !controlledByExtension;
         if (controlledByExtension) {
           var link = this.$['controlled-by'].querySelector('a');
           link.href = 'chrome://extensions#' + data.by_ext_id;
           link.textContent = data.by_ext_name;
         }
 
         var icon = 'chrome://fileicon/' + encodeURIComponent(data.file_path);
         this.iconLoader_.loadScaledIcon(this.$['file-icon'], icon);
       }
-
-      this.$.remove.style.visibility = hideRemove ? 'hidden' : '';
     },
 
     /** @private */
     computeCompletelyOnDisk_: function() {
       return this.data_.state == downloads.States.COMPLETE &&
              !this.data_.file_externally_removed;
     },
 
     /** @private */
     computeDate_: function() {
@@ skipping 14 matching lines @@
            this.data_.danger_type == downloads.DangerType.DANGEROUS_URL ||
            this.data_.danger_type == downloads.DangerType.POTENTIALLY_UNWANTED);
     },
 
     /** @private */
     computeIsDangerous_: function() {
       return this.data_.state == downloads.States.DANGEROUS;
     },
 
     /** @private */
+    computeRemoveStyle_: function() {
+      var canDelete = loadTimeData.getBoolean('allowDeletingHistory');
+      var hideRemove = this.isDangerous_ || this.showCancel_ || !canDelete;
+      return hideRemove ? 'visibility: hidden' : '';
+    },
+
+    /** @private */
     computeShowCancel_: function() {
       return this.data_.state == downloads.States.IN_PROGRESS ||
              this.data_.state == downloads.States.PAUSED;
     },
 
     /** @private */
     computeShowProgress_: function() {
       return this.showCancel_ && isFinite(this.data_.percent);
     },
 
@@ skipping 62 matching lines @@
     isIndeterminate_: function() {
       assert(this.showProgress_);
       return this.data_.percent == -1;
     },
 
     /** @private */
     onCancelClick_: function() {
       this.actionService_.cancel(this.data_.id);
     },
 
+    /** @private */
+    onDiscardDangerous_: function() {
+      this.actionService_.discardDangerous(this.data_.id);
+    },
+
     /**
      * @private
      * @param {Event} e
      */
     onDragStart_: function(e) {
       e.preventDefault();
       this.actionService_.drag(this.data_.id);
     },
 
     /**
      * @param {Event} e
      * @private
      */
     onFileLinkClick_: function(e) {
       e.preventDefault();
       this.actionService_.openFile(this.data_.id);
     },
 
     /** @private */
     onPauseClick_: function() {
       this.actionService_.pause(this.data_.id);
     },
 
     /** @private */
     onRemoveClick_: function() {
-      assert(!this.$.remove.disabled);
       this.actionService_.remove(this.data_.id);
     },
 
     /** @private */
-    onSaveDangerous_: function() {
-      this.actionService_.saveDangerous(this.data_.id);
-    },
-
-    /** @private */
-    onDiscardDangerous_: function() {
-      this.actionService_.discardDangerous(this.data_.id);
-    },
-
-    /** @private */
     onResumeClick_: function() {
       this.actionService_.resume(this.data_.id);
     },
 
     /** @private */
     onRetryClick_: function() {
       this.actionService_.download(this.$['file-link'].href);
     },
 
     /** @private */
+    onSaveDangerous_: function() {
+      this.actionService_.saveDangerous(this.data_.id);
+    },
+
+    /** @private */
     onScrollbarWidthChange_: function() {
       if (!this.$)
         return;
 
       var endCap = this.$['end-cap'];
       endCap.style.flexBasis = '';
 
       if (this.scrollbarWidth) {
         var basis = parseInt(getComputedStyle(endCap).flexBasis, 10);
         endCap.style.flexBasis = basis - this.scrollbarWidth + 'px';
       }
     },
 
     /** @private */
     onShowClick_: function() {
       this.actionService_.show(this.data_.id);
     },
   });
 
   return {Item: Item};
 });