Add button to add new FSP services to Files app.

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>
   <message name="IDS_CHROMEBOOK" desc="The localized name for Chromebook.">
     Chromebook
   </message>
   <message name="IDS_CHROMEBOX" desc="The localized name for Chromebox">
@@ skipping 226 matching lines @@
   </message>
   <message name="IDS_FILE_BROWSER_FORMAT_DEVICE_BUTTON_LABEL" desc="Title of the action for formatting removable device.">
     Format device
   </message>
   <message name="IDS_FILE_BROWSER_UNMOUNT_DEVICE_BUTTON_LABEL" desc="Title of the action for unmounting removable device.">
     Eject device
   </message>
   <message name="IDS_FILE_BROWSER_CLOSE_VOLUME_BUTTON_LABEL" desc="Title of the action for closing either an archive volume or a volume provided by an extension.">
     Close
   </message>
+  <message name="IDS_FILE_BROWSER_ADD_NEW_SERVICES_BUTTON_LABEL" desc="Title of the button in the left nav to add new services (file systems) to Files app.">
+    Add new services
+  </message>
   <message name="IDS_FILE_BROWSER_ACTION_VIEW" desc="Title of the action to view (no edit) a file.">
     View
   </message>
   <message name="IDS_FILE_BROWSER_ACTION_OPEN" desc="Title of the action to open (and possibly edit) a file.">
     Open
   </message>
   <message name="IDS_FILE_BROWSER_ACTION_OPEN_GDOC" desc="Title of the action to open a Google Docs document.">
     Docs
   </message>
   <message name="IDS_FILE_BROWSER_ACTION_OPEN_GSHEET" desc="Title of the action to open a Google Spreadsheets document.">
@@ skipping 414 matching lines @@
   <message name="IDS_FILE_BROWSER_UNSUPPORTED_FILESYSTEM_WARNING" desc="Displayed when device contents cannot be read because filesystem is unsupported.">
     This device cannot be opened because its filesystem is not supported.
   </message>
   <message name="IDS_FILE_BROWSER_FORMATTING_WARNING" desc="Displayed when you attempt to format device.">
     Formatting the removable media is going to erase all data. Do you wish to continue?
   </message>
 
   <message name="IDS_FILE_BROWSER_SUGGEST_DIALOG_TITLE" desc="Title of the suggest app dialog, which shows the list of the apps which supports the selected file.">
     Select an app to open this file
   </message>
+  <message name="IDS_FILE_BROWSER_SUGGEST_DIALOG_FOR_PROVIDERS_TITLE" desc="Title of the suggest app dialog, which shows the list of the apps that can be added to the left nav of Files app.">
+    Available services
+  </message>
   <message name="IDS_FILE_BROWSER_SUGGEST_DIALOG_LINK_TO_WEBSTORE" desc="Text of the link to the app list on Chrome Webstore, which shows the more apps than in the suggest app dialog.">
     See more...
   </message>
   <message name="IDS_FILE_BROWSER_SUGGEST_DIALOG_INSTALLATION_FAILED" desc="Error message when the installation of the app from WebStore is failed.">
     Installation failed.
   </message>
 
   <message name="IDS_FILE_BROWSER_SELECT_FOLDER_TITLE" desc="Select folder title.">
     Select a folder to open
   </message>
@@ skipping 5492 matching lines @@
   <message name="IDS_OPTIONS_RESOLVE_TIMEZONE_BY_GEOLOCATION_DESCRIPTION" desc="Label for checkbox to allow automatic timezone update by user geolocation.">
     Set time zone automatically using your location
   </message>
   <message name="IDS_FLAGS_ENABLE_FIREWALL_HOLE_PUNCHING_NAME" desc="Name of the option to enable punching holes in the Chrome OS firewall.">
     Enable firewall hole punching.
   </message>
   <message name="IDS_FLAGS_ENABLE_FIREWALL_HOLE_PUNCHING_DESCRIPTION" desc="Description of the option to enable punching holes in the Chrome OS firewall.">
     Enable punching holes in the Chrome OS firewall for Chrome Apps that open a TCP/IP server socket or UDP socket.
   </message>
 </grit-part>