Implement restart-required message on Linux.

chrome/app/google_chrome_strings.grd

 <?xml version="1.0" encoding="UTF-8"?>
 <!-- This file contains definitions of strings that are specific to
 Google Chrome. These strings will be translated for each locale that Google
 Chrome supports. If you update this file, be sure also to update
 chromium_strings.grd. -->
 
 <grit base_dir="." latest_public_release="0" current_release="1"
       output_all_resource_defines="false" source_lang_id="en" enc_check="möl">
   <outputs>
     <output filename="grit/google_chrome_strings.h" type="rc_header">
@@ skipping 1191 matching lines @@
       </message>
       <message name="IDS_PAGE_INFO_SECURITY_TAB_SECURE_IDENTITY_CT_INVALID" desc="The text of the identity section when the page is secure, but it contains a Signed Certificate Timestamp from a known Certificate Transparency log that failed to verify.">
         Chrome verified that <ph name="ISSUER">$1<ex>VeriSign</ex></ph> issued this website's certificate. The server supplied Certificate Transparency information, but it was invalid.
       </message>
 
       <!-- Desktop Capture -->
       <message name="IDS_DESKTOP_MEDIA_PICKER_SOURCE_TYPE_TAB" desc="Text for the button on the window picker dialog, clicking which takes one to tab sharing">
         Chrome Tab
       </message>
 
+      <!-- Plugin Placeholders -->
+      <message name="IDS_PLUGIN_RESTART_REQUIRED" desc="The placeholder text for a plugin that can't be loaded until the browser is restarted.">
+        Restart Chrome to enable <ph name="PLUGIN_NAME">$1<ex>Flash</ex></ph>
+      </message>
+
       <!-- Runtime permission strings -->
       <if expr="is_android">
         <message name="IDS_INFOBAR_MISSING_CAMERA_PERMISSION_TEXT" desc="Text shown in an infobar when a website has requested access to the camera capabilities, but Chrome is missing the Android camera permission.">
           Chrome needs camera access to share it with this site.
         </message>
         <message name="IDS_INFOBAR_MISSING_MICROPHONE_PERMISSION_TEXT" desc="Text shown in an infobar when a website has requested access to the microphone capabilities, but Chrome is missing the Android microphone permission.">
           Chrome needs microphone access to share it with this site.
         </message>
         <message name="IDS_INFOBAR_MISSING_LOCATION_PERMISSION_TEXT" desc="Text shown in an infobar when a website has requested access to the location capabilities, but Chrome is missing the Android location permission.">
           Chrome needs location access to share it with this site.
@@ skipping 63 matching lines @@
           Pin Chrome to your taskbar
         </message>
         <message name="IDS_WIN10_WELCOME_SELECT" desc="An instruction asking the user to select Chrome from an external list of apps.">
           Select <ph name="SMALL_PRODUCT_LOGO">&lt;div class="logo-small"&gt;&lt;/div&gt;</ph> <ph name="BEGIN_BOLD">&lt;strong&gt;</ph>Google Chrome<ph name="END_BOLD">&lt;/strong&gt;</ph>
         </message>
       </if>
 
     </messages>
   </release>
 </grit>