Removing unused string for pop-ups menu.

The pop-up string has been replaced with pop-ups and redirects.  I've removed the old string, which will no longer be referenced after crrev.com/c/1047687.

Bug: 840356
Change-Id: Iaf65ce22e3296215f27d25dfa7b7a81b0c605758
Reviewed-on: https://chromium-review.googlesource.com/1053953Reviewed-by: Patti <patricialor@chromium.org>
Commit-Queue: Eric Robinson <ericrobinson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558180}

components/page_info_strings.grdp

@@ -212,9 +212,6 @@
     <message name="IDS_PAGE_INFO_TYPE_JAVASCRIPT" desc="The label used for JavaScript permission controls in the Page Info popup.">
       JavaScript
     </message>
-    <message name="IDS_PAGE_INFO_TYPE_POPUPS" desc="The label used for popups permission controls in the Page Info popup.">
-      Popups
-    </message>
     <message name="IDS_PAGE_INFO_TYPE_POPUPS_REDIRECTS" desc="The label used for the popup/redirect permission controls in the Page Info popup.">
       Pop-ups and redirects
     </message>