Correctly handle out of storage space and "actively importing" states in controller.

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 430 matching lines @@
   </message>
   <message name="IDS_FILE_BROWSER_REMOVE_FOLDER_SHORTCUT_BUTTON_LABEL" desc="Menu item label, unpinning the selected folder from the left nav.">
     Remove shortcut
   </message>
   <message name="IDS_FILE_BROWSER_SHARE_BUTTON_LABEL" desc="Menu item label, showing dialog to share the selected file.">
     Share
   </message>
   <message name="IDS_FILE_BROWSER_CLOUD_IMPORT_BUTTON_LABEL" desc="Label for button that initiates media backup to the cloud.">
     Import <ph name="FILE_COUNT">$1<ex>5</ex></ph> files to Google Drive
   </message>
+  <message name="IDS_FILE_BROWSER_CLOUD_IMPORT_ACTIVE_IMPORT_BUTTON_LABEL" desc="Message to user that there is an active import in progress.">
+    Importing...
+  </message>
   <message name="IDS_FILE_BROWSER_CLOUD_IMPORT_EMPTY_SCAN_BUTTON_LABEL" desc="Message to user that no new files were found, so cloud import is not possible.">
     No new media
   </message>
   <message name="IDS_FILE_BROWSER_CLOUD_IMPORT_INSUFFICIENT_SPACE_BUTTON_LABEL" desc="Message to user that there is not enough space to perform a cloud import.">
     Insufficient space on your device!
   </message>
   <message name="IDS_FILE_BROWSER_CLOUD_IMPORT_SCANNING_BUTTON_LABEL" desc="Label for button showing that scanning is in progress...prior to being enabled when scanning is complete.">
     Scanning your media...
   </message>
   <message name="IDS_FILE_BROWSER_CLOUD_IMPORT_ITEMS_REMAINING" desc="File Manager status message.">
@@ skipping 5561 matching lines @@
   <message name="IDS_SET_TIME_BUTTON_CLOSE" desc="Text for the button to close the window.">
     Done
   </message>
   <message name="IDS_SET_TIME_DATE_LABEL" desc="Label for the date input element.">
     System date
   </message>
   <message name="IDS_SET_TIME_TIME_LABEL" desc="Label for the time input element.">
     System time
   </message>
 </grit-part>