MD User Manager: Refactors existing dialogs in User Manager into <user-manager-dialog>

chrome/browser/resources/md_user_manager/user_manager_dialog.html

+<link rel="import" href="chrome://md-user-manager/shared_styles.html">
+<link rel="import" href="chrome://resources/cr_elements/icons.html">
+<link rel="import" href="chrome://resources/html/polymer.html">
+<link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/classes/iron-flex-layout.html">
+<link rel="import" href="chrome://resources/polymer/v1_0/paper-dialog-behavior/paper-dialog-behavior.html">
+<link rel="import" href="chrome://resources/polymer/v1_0/paper-dialog-behavior/paper-dialog-shared-styles.html">
+<link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button.html">
+
+<dom-module id="user-manager-dialog">
+  <template>
+    <style include="shared-styles paper-dialog-shared-styles">
+      :host {
+        --paper-dialog: {
+          border-radius: 2px;
+          color: var(--primary-text-color);
+          font-size: inherit;
+          line-height: initial;
+          width: 512px;
+        };
+      }
+
+      :host ::content > *,
+      :host > ::content > *:first-child,
+      :host > ::content > *:last-child {
+        /* Overrides paper-dialog-shared-styles. */
+        margin: 0;
+        padding: 0;
+      }
+
+      #title-bar {
+        align-items: center;
+        border-bottom: var(--user-manager-separator-line);
+        min-height: 52px;
+        @apply(--user-manager-dialog-title-bar);
+      }
+
+      #close {
+        --paper-icon-button: {
+          height: 40px;
+          padding: 10px;
+          width: 40px;
+        };
+        -webkit-margin-end: 6px;
+        -webkit-margin-start: auto;
+        flex-shrink: 0;
+      }
+
+      :host ::content .title {
+        -webkit-margin-end: 10px;
+        -webkit-margin-start: 16px;
+        font-size: 16px;
+      }
+
+      :host ::content .body > * {
+        padding: 0 16px;
+      }
+
+      :host ::content .body > .no-padding {
+        padding: 0;
+      }
+
+      :host ::content .footer {
+        margin-top: 20px;
+        padding: 16px;
+      }
+    </style>
+    <div id="title-bar" class="horizontal justified layout">
+      <content select=".title"></content>
+      <paper-icon-button icon="cr:close" id="close" dialog-dismiss>
+      </paper-icon-button>
+    </div>
+    <content select=".body"></content>
+    <content select=".footer"></content>
+  </template>
+  <script src="chrome://md-user-manager/user_manager_dialog.js"></script>
+</dom-module>