MD Settings: Add "Auto Open" setting to Downloads page UI.

chrome/app/settings_strings.grdp

Index: chrome/app/settings_strings.grdp
diff --git a/chrome/app/settings_strings.grdp b/chrome/app/settings_strings.grdp
index 13328e251993e6c7a39f387c6f602d7c404bb850..39e53724eeb94b25601a70f15b1baf16830292e8 100644
--- a/chrome/app/settings_strings.grdp
+++ b/chrome/app/settings_strings.grdp
@@ -314,6 +314,9 @@
   <message name="IDS_SETTINGS_CONTROLLED_BY_EXTENSION" desc="Label text of an indicator that a setting's value is being controlled by an extension.">
     <ph name="NAME">$1<ex>Adblocker plusplus</ex></ph> is controlling this setting
   </message>
+  <message name="IDS_SETTINGS_CLEAR" desc="Label used on a menu item or button to clear an item.">
+    Clear
+  </message>
   <message name="IDS_SETTINGS_EDIT" desc="Label used on a menu item or button, used in different contexts to edit an item.">
     Edit
   </message>
@@ -995,6 +998,9 @@
   <message name="IDS_SETTINGS_DISCONNECT_GOOGLE_DRIVE" desc="Label for the checkbox which enables disconnecting from Google Drive account.">
     Disconnect Google Drive account
   </message>
+  <message name="IDS_SETTINGS_OPEN_FILE_TYPES_AUTOMATICALLY" desc="The information label for the 'Clear auto-opening settings' button">
+    Open certain file types automatically after downloading
+  </message>
 
   <if expr="chromeos">
     <!-- Date/Time Page -->