MD History: Add basic material design history cards and history items

chrome/browser/resources/md_history/history-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.
+
+Polymer({
+  is: 'history-item',
+  properties: {
+    timeAccessed: {
+      type: String,
+      value: ''
+    },
+    websiteTitle: {
+      type: String,
+      value: ''
+    },
+    // Domain is the website text shown on the history-item next to the title.
+    // Gives the user some idea of which history items are different pages
+    // belonging to the same site, and can be used to look for more items
+    // from the same site.
+    websiteDomain: {
+      type: String,
+      value: ''
+    },
+    // The website url is used to define where the link should take you if
+    // you click on the title, and also to define which icon the history-item
+    // should display.
+    websiteUrl: {
+      type: String,
+      value: '',
+      observer: 'showIcon_'
+    },
+    // If the website is a bookmarked page starred is true.
+    starred: {
+      type: Boolean,
+      value: false,
+      reflectToAttribute: true
+    },
+    // The time in seconds of when the website was accessed.
+    timestamp: {
+      type: Number,
+      value: 0
+    },
+    selected: {
+      type: Boolean,
+      value: false,
+      notify: true
+    }

[Dan Beam, 2016/01/16 02:54:36]

nit: arguably \n between each property

[yingran, 2016/01/18 05:40:30]

Done.

+  },
+
+  /**
+   * When a history-item is selected the toolbar is notified and increases
+   * or decreases its count of selected items accordingly.
+   * @private
+   */
+  checkboxSelected: function() {
+    this.fire('history-checkbox-select', {
+      countAddition: this.$.checkbox.checked ? 1 : -1
+    });
+  },
+
+  /**
+   * When the url for the history-item is set, the icon associated with this
+   * website is also set.
+   * @private
+   */
+  showIcon_: function() {
+    this.$['website-icon'].style.backgroundImage = '-webkit-image-set(' +
+          'url(chrome://favicon/size/16@1x/' + this.websiteUrl + ') 1x,' +
+          'url(chrome://favicon/size/16@2x/' + this.websiteUrl + ') 2x)';
+  },
+
+  /**
+   * Fires a custom event when the menu button is clicked. Sends the details of
+   * the history item and where the menu should appear.
+   */
+  openMenu: function(e) {
+    var position = this.$['menu-button'].getBoundingClientRect();
+
+    this.fire('toggle-menu', {
+      x: position.left,
+      y: position.top,
+      accessTime: this.timestamp
+    });
+    // Stops the 'tap' event from closing the menu when it opens.
+    e.stopPropagation();
+  }
+});