WebUI: fixes imports in assistant-optin UI.

This CL changes imports from iron-icons.html to iron-icon.html (without S),
as well as moving element imports to where it's used.

Bug: 855205
Change-Id: Ibe22c21ec9270258efafd1e06fed73de1d226f2d
Reviewed-on: https://chromium-review.googlesource.com/1145598
Commit-Queue: Scott Chen <scottchen@chromium.org>
Reviewed-by: Yue Li <updowndota@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577284}

chrome/browser/resources/chromeos/assistant_optin/assistant_confirm_reject.html

@@ -3,6 +3,7 @@
      found in the LICENSE file. -->
 
 <link rel="import" href="chrome://resources/cr_elements/cr_radio_button/cr_radio_button.html">
+<link rel="import" href="chrome://resources/polymer/v1_0/iron-icon/iron-icon.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-radio-group/paper-radio-group.html">
 <dom-module id="assistant-confirm-reject">
   <template>

chrome/browser/resources/chromeos/assistant_optin/assistant_get_more.html

@@ -2,6 +2,7 @@
      Use of this source code is governed by a BSD-style license that can be
      found in the LICENSE file. -->
 
+<link rel="import" href="chrome://resources/polymer/v1_0/iron-icon/iron-icon.html">
 <dom-module id="assistant-get-more">
   <template>
     <link rel="stylesheet" href="../login/oobe_flex_layout.css">

chrome/browser/resources/chromeos/assistant_optin/assistant_loading.html

@@ -4,6 +4,8 @@
 
 <link rel="import" href="chrome://resources/cr_elements/cr_expand_button/cr_expand_button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-collapse/iron-collapse.html">
+<link rel="import" href="chrome://resources/polymer/v1_0/iron-icon/iron-icon.html">
+<link rel="import" href="chrome://resources/polymer/v1_0/paper-progress/paper-progress.html">
 <dom-module id="assistant-loading">
   <template>
     <link rel="stylesheet" href="../login/oobe_flex_layout.css">

chrome/browser/resources/chromeos/assistant_optin/assistant_optin.html

@@ -12,8 +12,6 @@
 <link rel="import" href="chrome://oobe/custom_elements.html">
 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
 <link rel="import" href="chrome://resources/html/util.html">
-<link rel="import" href="chrome://resources/polymer/v1_0/iron-icons/iron-icons.html">
-<link rel="import" href="chrome://resources/polymer/v1_0/paper-progress/paper-progress.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-styles/color.html">
 <link rel="import" href="chrome://resources/cr_elements/cr_icons_css.html">
 <link rel="import" href="chrome://resources/cr_elements/paper_button_style_css.html">

chrome/browser/resources/chromeos/assistant_optin/assistant_ready.html

@@ -2,6 +2,7 @@
      Use of this source code is governed by a BSD-style license that can be
      found in the LICENSE file. -->
 
+<link rel="import" href="chrome://resources/polymer/v1_0/iron-icon/iron-icon.html">
 <dom-module id="assistant-ready">
   <template>
     <link rel="stylesheet" href="../login/oobe_flex_layout.css">

chrome/browser/resources/chromeos/assistant_optin/assistant_third_party.html

@@ -2,6 +2,7 @@
      Use of this source code is governed by a BSD-style license that can be
      found in the LICENSE file. -->
 
+<link rel="import" href="chrome://resources/polymer/v1_0/iron-icon/iron-icon.html">
 <dom-module id="assistant-third-party">
   <template>
     <link rel="stylesheet" href="../login/oobe_flex_layout.css">

chrome/browser/resources/chromeos/assistant_optin/setting_zippy.html

@@ -5,7 +5,6 @@
 <link rel="import" href="chrome://resources/cr_elements/cr_expand_button/cr_expand_button.html">
 <link rel="import" href="chrome://resources/cr_elements/cr_toggle/cr_toggle.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-collapse/iron-collapse.html">
-<link rel="import" href="chrome://resources/polymer/v1_0/iron-icons/iron-icons.html">
 <dom-module id="setting-zippy">
   <template>
     <link rel="stylesheet" href="setting_zippy.css">