MD Settings: Allow controlled-button to be used with icons.

chrome/app/settings_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Settings-specific strings (included from generated_resources.grd). -->
 <grit-part>
   <!-- About Page -->
   <message name="IDS_SETTINGS_ABOUT_PAGE_BROWSER_VERSION" desc="The text label describing the version of the browser, example: Version 57.0.2937.0 (Developer Build) unknown (64-bit)">
     Version <ph name="PRODUCT_VERSION">$1<ex>15.0.865.0</ex></ph> (<ph name="PRODUCT_CHANNEL">$2<ex>Developer Build</ex></ph>) <ph name="PRODUCT_MODIFIER">$3</ph> <ph name="PRODUCT_VERSION_BITS">$4</ph>
   </message>
   <if expr="chromeos">
     <message name="IDS_SETTINGS_ABOUT_PAGE_DETAILED_BUILD_INFO" desc="Label describing the section that shows detailed information about the current Chrome build.">
       Detailed build information
@@ skipping 958 matching lines @@
     Set up cloud printing devices
   </message>
 
   <!-- Downloads Page -->
   <message name="IDS_SETTINGS_DOWNLOADS" desc="Name of the settings page which displays download preferences.">
     Downloads
   </message>
   <message name="IDS_SETTINGS_DOWNLOAD_LOCATION" desc="Label for the input which allows the user to specify the default download directory.">
     Location
   </message>
-  <message name="IDS_SETTINGS_CHANGE_DOWNLOAD_LOCATION" desc="Text for the button which allows the user to change the default download directory.">
-    Change
-  </message>
   <message name="IDS_SETTINGS_PROMPT_FOR_DOWNLOAD" desc="Label for the checkbox which enables a prompt for the user to choose a download location for each download instead of using the default.">
     Ask where to save each file before downloading
   </message>
   <message name="IDS_SETTINGS_DISCONNECT_GOOGLE_DRIVE" desc="Label for the checkbox which enables disconnecting from Google Drive account.">
     Disconnect Google Drive account
   </message>
 
   <if expr="chromeos">
     <!-- Date/Time Page -->
     <message name="IDS_SETTINGS_DATE_TIME" desc="Name of the settings page which displays date and time preferences.">
@@ skipping 1781 matching lines @@
       System
     </message>
     <message name="IDS_SETTINGS_SYSTEM_HARDWARE_ACCELERATION_LABEL" desc="Label for the checkbox that forces Chrome to render via hardware acceleration (GPU) when available.">
       Use hardware acceleration when available
     </message>
     <message name="IDS_SETTINGS_SYSTEM_PROXY_SETTINGS_BUTTON" desc="Text for the button that changes a user's network proxy settings.">
       Change proxy settings
     </message>
   </if>
 </grit-part>