webapps: allow callers of icon downloader/selector to specify a minimum size

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 176 matching lines @@
     <dimen name="find_result_bar_min_gap_between_stacks">3px</dimen>
     <dimen name="find_result_bar_stacked_result_height">3px</dimen>
     <dimen name="find_in_page_separator_width">1dp</dimen>
     <dimen name="find_in_page_popup_width">375dp</dimen>
     <dimen name="find_in_page_popup_height">60dp</dimen>
     <dimen name="find_in_page_popup_margin_end">62dp</dimen>
 
     <!-- Web app dimensions -->
     <dimen name="webapp_splash_image_size">128dp</dimen>
     <dimen name="webapp_home_screen_icon_size">48dp</dimen>
+    <dimen name="webapp_splash_image_min_size">48dp</dimen>
 
     <!-- Toolbar dimensions -->
     <dimen name="toolbar_tab_count_text_size_1_digit">12dp</dimen>
     <dimen name="toolbar_tab_count_text_size_2_digit">10dp</dimen>
     <dimen name="toolbar_height_no_shadow">56dp</dimen>
 
     <dimen name="location_bar_margin_top">5dp</dimen>
     <dimen name="location_bar_margin_bottom">5dp</dimen>
 
     <dimen name="toolbar_edge_padding">8dp</dimen>
@@ skipping 84 matching lines @@
     <dimen name="default_favicon_size">16dp</dimen>
 
     <!-- Media UI dimensions -->
     <!-- The media_session_icon_size is just big enough to make sure Android doesn't discard the
          icon but otherwise, the icon is meant to be a flat color so it doesn't really matter. -->
     <dimen name="media_session_icon_size">48dp</dimen>
 
     <!-- Offline pages dimensions -->
     <dimen name="offline_page_item_vertical_spacing">40dp</dimen>
 </resources>