Remove ellipsis from "Set wallpaper..." context menu item.

chrome/app/chromeos_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- ChromeOS-specific strings (included from generated_resources.grd).
      Everything in this file is wrapped in <if expr="chromeos">. -->
 <grit-part>
   <message name="IDS_EMPTY_STRING" desc="Empty string, exist only to make code generic. No translation required.">
   </message>
   <!-- Idle logout dialog for retail mode -->
   <message name="IDS_IDLE_LOGOUT_TITLE" desc="Dialog title for the idle logout dialog. Used in retail mode only.">
     Are you still there?
   </message>
@@ skipping 103 matching lines @@
   </message>
   <message name="IDS_FILE_BROWSER_DOWNLOADS_DIRECTORY_LABEL" desc="Downloads local directory label.">
     Downloads
   </message>
   <message name="IDS_FILE_BROWSER_DOWNLOADS_DIRECTORY_WARNING" desc="Warning displayed to user when viewing downloads folder.">
     <ph name="BEGIN_BOLD">&lt;strong&gt;</ph>Caution:<ph name="END_BOLD">&lt;/strong&gt;</ph>  These files are temporary and may be automatically deleted to free up disk space.  <ph name="BEGIN_LINK">&lt;a href="javascript://"&gt;</ph>Learn More<ph name="END_LINK">&lt;/a&gt;<ex>&lt;/a&gt;</ex></ph>
   </message>
   <message name="IDS_FILE_BROWSER_NAME_COLUMN_LABEL" desc="Name column label.">
     Name
   </message>
+  <message name="IDS_FILE_BROWSER_SET_WALLPAPER_MENU_ITEM" desc="The context menuitem to set wallpaper.">

[fukino, 2016/06/21 17:31:30]

You should check how other similar UI elements are defined/named.
For example, please try to be consistent with
IDS_FILE_BROWSER_ZIP_SELECTION_BUTTON_LABEL

[fukino, 2016/06/21 17:31:30]

s/menuitem/menu item

It's weird to insert this item between column labels.

+    Set wallpaper
+  </message>
   <message name="IDS_FILE_BROWSER_SIZE_COLUMN_LABEL" desc="Size column label.">
     Size
   </message>
 
   <message name="IDS_FILE_BROWSER_SIZE_BYTES" desc="Size in bytes.">
     $1 bytes
   </message>
   <message name="IDS_FILE_BROWSER_SIZE_KB" desc="Size in kilo bytes.">
     $1 KB
   </message>
@@ skipping 6523 matching lines @@
   <message name="IDS_ARC_ANDROID_MANAGEMENT_REQUIRED_ERROR" desc="Error message shown when Android management is required for an unmanaged Chrome OS user.">
     Your organization has not enabled Android Apps for your account. Contact your administrator for more information.
   </message>
   <message name="IDS_FLAGS_ENABLE_IME_MENU_NAME" desc="Name of the about: flag for enabling opt-in IME menu.">
     Enable opt-in IME menu
     </message>
   <message name="IDS_FLAGS_ENABLE_IME_MENU_DESCRIPTION" desc="Description of the about: flag for enabling opt-in IME menu.">
     Enable access to the new IME menu in the Language Settings page.
   </message>
 </grit-part>