[visual signals] Replace plural error message string

CL:2574116 removed a bunch of strings that were supposed to be unused.
That set included a string that was needed.

Restore the IDS_FILE_BROWSER_ERROR_PROGRESS_SUMMARY_PLURAL string.

Bug: 1160222
Change-Id: Ibea165663053237939c115f103a62a8ed58a055a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2599788Reviewed-by: Noel Gordon <noel@chromium.org>
Commit-Queue: Alex Danilo <adanilo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#838803}

chrome/browser/chromeos/file_manager/file_manager_string_util.cc

@@ -547,6 +547,8 @@ std::unique_ptr<base::DictionaryValue> GetFileManagerStrings() {
   SET_STRING("ERROR_LONG_NAME", IDS_FILE_BROWSER_ERROR_LONG_NAME);
   SET_STRING("ERROR_EXTERNAL_DRIVE_LONG_NAME",
              IDS_FILE_BROWSER_ERROR_EXTERNAL_DRIVE_LONG_NAME);
+  SET_STRING("ERROR_PROGRESS_SUMMARY_PLURAL",
+             IDS_FILE_BROWSER_ERROR_PROGRESS_SUMMARY_PLURAL);
   SET_STRING("ERROR_RENAMING", IDS_FILE_BROWSER_ERROR_RENAMING);
   SET_STRING("ERROR_RESERVED_NAME", IDS_FILE_BROWSER_ERROR_RESERVED_NAME);
   SET_STRING("ERROR_WHITESPACE_NAME", IDS_FILE_BROWSER_ERROR_WHITESPACE_NAME);

ui/chromeos/file_manager_strings.grdp

@@ -880,11 +880,12 @@
   <message name="IDS_FILE_BROWSER_RESTORE_FROM_TRASH_ERROR" desc="Message informing about error while restoring an item or items from the trash / recycle bin.">
     An error occurred. Some items may not have been restored.
   </message>
-
+  <message name="IDS_FILE_BROWSER_ERROR_PROGRESS_SUMMARY_PLURAL" desc="Summary message for multiple errors above the progress bar. This message may be placed at the next to ohter *_PROGERSS_SUMMARY messages.">
+    <ph name="COUNT">$1<ex>10</ex></ph> errors.
+  </message>
   <message name="IDS_FILE_BROWSER_PERCENT_COMPLETE" desc="Percentage of file operation that is complete in a progress message.">
     <ph name="PERCENT">$1<ex>10</ex></ph>% complete.
   </message>
-
   <message name="IDS_FILE_BROWSER_CANCEL_ACTIVITY_LABEL" desc="Text spoken by ChromeVox/screen reader describing what will be cancelled.">
     Cancel <ph name="ACTIVITY_DESCRIPTION">$1<ex>Copying file.txt</ex></ph>.
   </message>

ui/chromeos/file_manager_strings_grdp/IDS_FILE_BROWSER_ERROR_PROGRESS_SUMMARY_PLURAL.png.sha1

+c434fe2b53000bfa3af23be0f62fe2499e21dcb7
\ No newline at end of file