Add a <cr-input> element to cr_elements.

ui/webui/resources/cr_elements/cr_input/cr_input.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
+ * 'cr-input' is a single-line text field for user input. It is a convenience
+ * element composed of a 'paper-input-decorator' and a 'input is="core-input"'.
+ *
+ * Example:
+ *
+ *    <cr-input></cr-input>
+ *
+ * @group Chrome Elements
+ * @element cr-input
+ */
+Polymer('cr-input', {
+  publish: {
+    /**
+     * The label for this input. It normally appears as grey text inside
+     * the text input and disappears once the user enters text.
+     *
+     * @attribute label
+     * @type string
+     * @default ''
+     */
+    label: '',
+
+    /**
+     * If true, the label will "float" above the text input once the
+     * user enters text instead of disappearing.
+     *
+     * @attribute floatingLabel
+     * @type boolean
+     * @default true
+     */
+    floatingLabel: true,
+
+    /**
+     * Set to true to style the element as disabled.
+     *
+     * @attribute disabled
+     * @type boolean
+     * @default false
+     */
+    disabled: {value: false, reflect: true},
+
+    /**
+     * Set to true to mark the input as required.
+     *
+     * @attribute required
+     * @type boolean
+     * @default false
+     */
+    required: {value: false, reflect: true},
+
+    /**
+     * The current value of the input.
+     *
+     * @attribute value
+     * @type string
+     * @default ''
+     */
+    value: '',
+
+    /**
+     * The validation pattern for the input.
+     *
+     * @attribute pattern
+     * @type string
+     * @default ''
+     */
+    pattern: '',
+
+    /**
+     * The type of the input (password, date, etc.).
+     *
+     * @attribute type
+     * @type string
+     * @default 'text'
+     */
+    type: 'text',
+
+    /**
+     * The message to display if the input value fails validation. If this
+     * is unset or the empty string, a default message is displayed depending
+     * on the type of validation error.
+     *
+     * @attribute error
+     * @type string
+     * @default ''
+     */
+    error: '',
+
+    /**
+     * The most recently committed value of the input.
+     *
+     * @attribute committedValue
+     * @type string
+     * @default ''
+     */
+    committedValue: ''
+  },
+
+  /**
+   * Focuses the 'input' element.
+   */
+  focus: function() {
+    this.$.input.focus();
+  },
+

[stevenjb, 2015/02/24 23:39:59]

nit: FWIW, I still think that it would be good to establish a comment pattern
for fooChanged methods to make them easier to identify and provide a hint for
developers new to Polymer scanning this code.

+  valueChanged: function() {
+    this.$.decorator.updateLabelVisibility(this.value);
+  },
+
+  patternChanged: function() {
+    if (this.pattern)
+      this.$.input.pattern = this.pattern;
+    else
+      this.$.input.removeAttribute('pattern');
+  },
+
+  /** @override */
+  ready: function() {
+    this.$.events.forward(this.$.input, ['change']);
+    this.patternChanged();
+  },
+});