Convert chrome://extensions to a settings page within the options pages.

chrome/browser/resources/options/options.html

Index: chrome/browser/resources/options/options.html
===================================================================
--- chrome/browser/resources/options/options.html	(revision 99349)
+++ chrome/browser/resources/options/options.html	(working copy)
@@ -24,6 +24,7 @@
 <link rel="stylesheet" href="clear_browser_data_overlay.css">
 <link rel="stylesheet" href="content_settings.css">
 <link rel="stylesheet" href="cookies_view.css">
+<link rel="stylesheet" href="extension_settings.css">
 <link rel="stylesheet" href="font_settings.css">
 <if expr="pp_ifdef('enable_register_protocol_handler')">
   <link rel="stylesheet" href="handler_options.css">
@@ -34,6 +35,7 @@
 </if>
 <link rel="stylesheet" href="language_options.css">
 <link rel="stylesheet" href="manage_profile_overlay.css">
+<link rel="stylesheet" href="pack_extension_overlay.css">
 <link rel="stylesheet" href="password_manager.css">
 <link rel="stylesheet" href="password_manager_list.css">
 <link rel="stylesheet" href="personal_options.css">
@@ -88,6 +90,7 @@
   <include src="instant_confirm_overlay.html">
   <include src="language_add_language_overlay.html">
   <include src="manage_profile_overlay.html">
+  <include src="pack_extension_overlay.html">
   <include src="../sync_setup_overlay.html">
   <if expr="pp_ifdef('chromeos')">
      <include
@@ -126,6 +129,7 @@
            <include src="chromeos/accounts_options.html">
          </if>
          <include src="advanced_options.html">
+         <include src="extension_settings.html">
        </div>
        <div id="subpage-sheet-container-1"
            class="subpage-sheet-container transparent" hidden>