Created the dialog offering the user to merge their account data or keep it

chrome/android/java/res/values/dimens.xml

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Copyright 2014 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. -->
 
 <resources>
     <!-- Connection info popup dimensions -->
     <dimen name="connection_info_padding_wide">24dp</dimen>
     <dimen name="connection_info_padding_thin">16dp</dimen>
 
@@ skipping 149 matching lines @@
     <dimen name="badged_user_picture_width">46dp</dimen>
     <dimen name="badge_radius">10dp</dimen>
     <dimen name="badge_border_size">1.3dp</dimen>
 
     <!-- First Run Experience and Welcome Page dimensions -->
     <dimen name="fre_button_padding">12dp</dimen>
     <dimen name="fre_margin">24dp</dimen>
     <dimen name="fre_title_text_size">24sp</dimen>
     <dimen name="fre_button_text_size">14sp</dimen>
     <dimen name="fre_normal_text_size">14sp</dimen>
     <dimen name="fre_image_carousel_width">260dp</dimen>

[newt (away), 2016/02/25 06:25:53]

Delete this and other now-unused "fre" dimens.

[PEConn, 2016/02/25 14:19:51]

Done.

     <dimen name="fre_image_carousel_height">130dp</dimen>
     <dimen name="fre_checkmark_size">38dp</dimen>
     <dimen name="fre_tos_checkbox_padding">12dp</dimen>
 
+    <!-- Account Signin dimensions -->
+    <dimen name="signin_button_padding">12dp</dimen>
+    <dimen name="signin_margin">24dp</dimen>
+    <dimen name="signin_title_text_size">24sp</dimen>
+    <dimen name="signin_normal_text_size">14sp</dimen>
+    <dimen name="signin_image_carousel_width">260dp</dimen>
+    <dimen name="signin_image_carousel_height">130dp</dimen>
+
     <!-- Sign-in promo dimensions -->
     <dimen name="sign_in_promo_padding_bottom">16dp</dimen>
 
     <!-- Autofill card unmasking prompt dimensions -->
     <dimen name="autofill_card_unmask_tooltip_horizontal_padding">16dp</dimen>
     <dimen name="autofill_card_unmask_tooltip_vertical_padding">4dp</dimen>
 
     <!-- Alert dialog -->
     <dimen name="dialog_padding_top">@dimen/abc_dialog_padding_top_material</dimen>
     <dimen name="dialog_padding_sides">@dimen/abc_dialog_padding_material</dimen>
@@ skipping 130 matching lines @@
 
     <!-- Account chooser dialog dimensions -->
     <dimen name="account_chooser_dialog_margin">24dp</dimen>
     <dimen name="account_chooser_dialog_item_margin">20dp</dimen>
     <dimen name="account_chooser_dialog_title_main_text_size">18sp</dimen>
     <dimen name="account_chooser_dialog_title_descriptive_text_size">16sp</dimen>
 
     <!-- Clear browsing data preferences dimensions -->
     <dimen name="clear_browsing_data_checkbox_height">56dp</dimen>
 </resources>