WebUI: update empty-state strings for MD pages.

chrome/app/generated_resources.grd

 <?xml version="1.0" encoding="utf-8"?>
 
 <!--
 This file contains definitions of resources that will be translated for each
 locale.  The variables is_win, is_macosx, is_linux, and is_posix are available
 for making strings OS specific.  Other platform defines such as use_titlecase
 are declared in build/common.gypi.
 -->
 
 <grit base_dir="." latest_public_release="0" current_release="1"
@@ skipping 1527 matching lines @@
                desc="Tooltip text for the button that clears the search term on the downloads page.">
         Clear search
       </message>
       <message name="IDS_DOWNLOAD_SEARCHRESULTSFOR" desc="Format string for search results">
         Search results for '<ph name="SEARCH_STRING">$1</ph>'
       </message>
       <message name="IDS_DOWNLOAD_NO_SEARCH_RESULTS" desc="A message shown for when a search yield no results (no matching downloads).">
         No search results found
       </message>
       <message name="IDS_MD_DOWNLOAD_NO_DOWNLOADS" desc="A message shown when the user has no downloads to show on chrome://downloads.">
-        Nothing to see here...
+        Files you download appear here
       </message>
       <message name="IDS_DOWNLOAD_LINK_RESUME"
                desc="In the download view, 'Resume' link text">
         Resume
       </message>
       <message name="IDS_DOWNLOAD_LINK_REMOVE"
                desc="In the download view, 'Remove from list' link text">
         Remove from list
       </message>
       <message name="IDS_DOWNLOAD_LINK_CANCEL"
@@ skipping 10753 matching lines @@
       <message name="IDS_VIDEO_AUDIO_CALL_NOTIFICATION_TEXT_2" desc="Text to be shown as a notification when a WebRTC video and audio call is in progress" formatter_data="android_java">
         Accessing audio and video input
       </message>
       <message name="IDS_SCREEN_CAPTURE_NOTIFICATION_TEXT_2" desc="Text to be shown as a notification when screen capture is in progress.">
         Sharing screen
       </message>
     </if>
   </messages>
  </release>
 </grit>