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 229 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 5507 matching lines @@
   <message name="IDS_FILE_SYSTEM_REQUEST_FILE_SYSTEM_DIALOG_WRITABLE_MESSAGE" desc="Message in a prompt dialog for granting full permissions (read, write, delete, create files and directories) to a volume (eg. USB drive, SD card, MTP device) with the specified name to the extension.">
     Do you want to grant this app permission to read, write, delete and create files on <ph name="VOLUME_NAME">$1<ex>FooBar 4GB</ex>?</ph>
   </message>
   <message name="IDS_FILE_SYSTEM_REQUEST_FILE_SYSTEM_DIALOG_YES_BUTTON" desc="Label on the button to grant permissions.">
     Yes
   </message>
   <message name="IDS_FILE_SYSTEM_REQUEST_FILE_SYSTEM_DIALOG_NO_BUTTON" desc="Label on the button to reject permissions.">
     No
   </message>
 </grit-part>