Change PDF document's name string to meet formatting rules

This change modifies the PDF document's name string to follow formatting
rules defined in: http://userguide.icu-project.org/formatparse/messages

Bug: 1043505
Change-Id: I1cad4ecea83b41a1ccf7adb68ad3e2a104f65749
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2030350Reviewed-by: Kevin Babbitt <kbabbitt@microsoft.com>
Reviewed-by: Mustafa Emre Acer <meacer@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Virender Singh <virens@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#737212}

components/pdf_strings.grdp

@@ -61,9 +61,9 @@
          other {Page #}}
     </message>
     <message name="IDS_PDF_DOCUMENT_PAGE_COUNT" desc="Accessible name of PDF document. It gives information about the number of pages in the PDF file">
-      PDF document containing {COUNT, plural,
-      =1 {1 page}
-      other {# pages}}
+      {COUNT, plural,
+      =1 {PDF document containing {COUNT} page}
+      other {PDF document containing {COUNT} pages}}
     </message>
     <if expr="chromeos">
       <message name="IDS_PDF_DISCARD_FORM_CHANGES" desc="Title for a dialog that informs the user that the changes they have made to a form will be lost if they continue">