UI strings: expand PgUp and PgDwn to the full words.

ui/strings/ui_strings.grd

 <?xml version="1.0" encoding="UTF-8"?>
 
 <!-- This file contains definitions of resources that will be translated for
 each locale. Specifically, these are UI strings that are used by app/ that
 need to be translated for each locale.-->
 
 <grit base_dir="." latest_public_release="0" current_release="1"
       source_lang_id="en" enc_check="möl">
   <outputs>
     <!-- TODO add each of your output files.  Modify the three below, and add
@@ skipping 468 matching lines @@
       <message name="IDS_APP_HOME_KEY" desc="Home key">
         Home
       </message>
       <message name="IDS_APP_DELETE_KEY" desc="Delete key">
         Del
       </message>
       <message name="IDS_APP_END_KEY" desc="End key">
         End
       </message>
       <message name="IDS_APP_PAGEUP_KEY" desc="Page up key">
-        PgUp
+        Page Up
       </message>
       <message name="IDS_APP_PAGEDOWN_KEY" desc="Page down key">
-        PgDwn
+        Page Down
       </message>
       <message name="IDS_APP_LEFT_ARROW_KEY" desc="Left arrow key">
         Left Arrow
       </message>
       <message name="IDS_APP_RIGHT_ARROW_KEY" desc="Right arrow key">
         Right Arrow
       </message>
       <message name="IDS_APP_UP_ARROW_KEY" desc="Up arrow key">
         Up Arrow
       </message>
@@ skipping 189 matching lines @@
       </message>
       <message name="IDS_APP_LIST_SPEECH_HINT_TEXT" desc="The text label in the speech recognition UI to ask the user to speak the search query">
         Speak now
       </message>
       <message name="IDS_APP_LIST_SPEECH_NETWORK_ERROR_HINT_TEXT" desc="The text label in the speech recognition UI to show the speech recognition can't start because of network error.">
         No internet connection
       </message>
     </messages>
   </release>
 </grit>