Implement deletion of storage per site.

chrome/browser/resources/settings/site_settings/site_details.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.
 
 /**
  * @fileoverview
  * 'site-details' show the details (permissions and usage) for a given origin
  * under Site Settings.
  *
  * Example:
@@ skipping 25 matching lines @@
       observer: 'onOriginChanged_',
     },
 
     /**
      * The amount of data stored for the origin.
      */
     storedData_: {
       type: String,
       value: '',
     },
+
+    /**
+     * The type of storage for the origin.
+     */
+    storageType_: Number,
+
+    /**
+     * The category the user selected to get to this page.
+     */
+    categorySelected: String,
+
+    /**
+     * The current active route.
+     */
+    currentRoute: {
+      type: Object,
+      notify: true,
+    },
+  },
+
+  listeners: {
+    'usage-deleted': 'onUsageDeleted',
   },
 
   ready: function() {
     this.$.cookies.category = settings.ContentSettingsTypes.COOKIES;
     this.$.javascript.category = settings.ContentSettingsTypes.JAVASCRIPT;
     this.$.popups.category = settings.ContentSettingsTypes.POPUPS;
     this.$.geolocation.category = settings.ContentSettingsTypes.GEOLOCATION;
     this.$.notification.category = settings.ContentSettingsTypes.NOTIFICATIONS;
     this.$.fullscreen.category = settings.ContentSettingsTypes.FULLSCREEN;
     this.$.camera.category = settings.ContentSettingsTypes.CAMERA;
     this.$.mic.category = settings.ContentSettingsTypes.MIC;
   },
 
   /**
    * Handler for when the origin changes.
    */
   onOriginChanged_: function() {
     var url = /** @type {{hostname: string}} */(new URL(this.origin));
     this.$.usageApi.fetchUsageTotal(url.hostname);
   },
 
   /**
    * Clears all data stored for the current origin.
    */
   onClearStorage_: function() {
-    // TODO(finnur): Implement.
+    this.$.usageApi.clearUsage(this.origin, this.storageType_);
   },
 
   /**
+   * Called when usage has been deleted for an origin.
+   */
+  onUsageDeleted: function(event) {
+    if (event.detail.origin == this.origin) {
+      this.storedData_ = '';
+      this.navigateBackIfNoData_();
+    }
+  },
+
+  /**
    * Resets all permissions and clears all data stored for the current origin.
    */
   onClearAndReset_: function() {
     Array.prototype.forEach.call(
         this.root.querySelectorAll('site-details-permission'),
         function(element) { element.resetPermission(); });
 
-    this.onClearStorage_();
+    if (this.storedData_ != '')
+      this.onClearStorage_();
+    else
+      this.navigateBackIfNoData_();
+  },
+
+  /**
+   * Navigate back if the UI is empty (everything been cleared).
+   */
+  navigateBackIfNoData_: function() {
+    if (this.storedData_ == '' && !this.permissionShowing_())
+      this.fire('subpage-back');
+  },
+
+  /**
+   * Returns true if one or more permission is showing.
+   */
+  permissionShowing_: function() {
+    return Array.prototype.some.call(
+        this.root.querySelectorAll('site-details-permission'),
+        function(element) { return element.offsetHeight > 0; });
   },
 });