Implement window.alert() and its cousins for extensions....

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. -->
 
 <grit base_dir="." latest_public_release="0" current_release="1"
       source_lang_id="en" enc_check="möl">
   <outputs>
     <output filename="grit/generated_resources.h" type="rc_header">
       <emit emit_type='prepend'></emit>
@@ skipping 2733 matching lines @@
         About Version
       </message>
       <message name="IDS_ABOUT_VERSION_OFFICIAL" desc="official build on the about:version page">
         Official Build
       </message>
       <message name="IDS_ABOUT_VERSION_UNOFFICIAL" desc="unofficial build on the about:version page">
         Developer Build
       </message>
 
       <!-- Javascript Dialog Box strings -->
-      <message name="IDS_JAVASCRIPT_ALERT_DEFAULT_TITLE" desc="Title for Javascript alert if there is no hostname to display">
+      <message name="IDS_JAVASCRIPT_ALERT_DEFAULT_TITLE" desc="Title for Javascript alert originating from a web page if there is no hostname to display">
         Javascript Alert
       </message>
-      <message name="IDS_JAVASCRIPT_MESSAGEBOX_DEFAULT_TITLE" desc="Title for Javascript prompt and confirm if there is no hostname to display">
+      <message name="IDS_JAVASCRIPT_MESSAGEBOX_DEFAULT_TITLE" desc="Title for Javascript prompt and confirm originating from a web page if there is no hostname to display">
         Javascript
       </message>
-      <message name="IDS_JAVASCRIPT_ALERT_TITLE" desc="Title for Javascript alert">
+      <message name="IDS_JAVASCRIPT_ALERT_TITLE" desc="Title for Javascript alert originating from a web page">
         Alert <ph name="SITE">$1<ex>http://www.google.com</ex>
         </ph>
       </message>
-      <message name="IDS_JAVASCRIPT_MESSAGEBOX_TITLE" desc="Title for Javascript prompt and confirm">
+      <message name="IDS_JAVASCRIPT_MESSAGEBOX_TITLE" desc="Title for Javascript prompt and confirm originating from a web page">
         <ph name="SITE">$1<ex>http://www.google.com</ex></ph>
       </message>
+      <message name="IDS_EXTENSION_ALERT_DEFAULT_TITLE" desc="Title for Javascript alert originating from an extension if there is no extension name to display">
+        Extension Alert
+      </message>
+      <message name="IDS_EXTENSION_MESSAGEBOX_DEFAULT_TITLE" desc="Title for Javascript prompt and confirm originating from an extension if there is no extension name to display">
+        Extension
+      </message>
+      <message name="IDS_EXTENSION_ALERT_TITLE" desc="Title for Javascript alert originating from an extension">
+        Extension Alert <ph name="EXTENSION_NAME">$1<ex>Gmail Checker</ex></ph>
+      </message>
+      <message name="IDS_EXTENSION_MESSAGEBOX_TITLE" desc="Title for Javascript prompt and confirm originating from an extension">
+        Extension <ph name="EXTENSION_NAME">$1<ex>Gmail Checker</ex></ph>
+      </message>
       <message name="IDS_JAVASCRIPT_MESSAGEBOX_SUPPRESS_OPTION" desc="Optional UI shown on the message box, in the form of a checkbox, allowing the user to suppress additional message boxes from the page.">
         Prevent this page from creating additional dialogs.
       </message>
 
       <!-- "Before Unload" Dialog Box strings -->
       <message name="IDS_BEFOREUNLOAD_MESSAGEBOX_TITLE" desc="Title for the 'before unload' dialog.">
         Confirm Navigation
       </message>
       <message name="IDS_BEFOREUNLOAD_MESSAGEBOX_FOOTER" desc="Text shown at the bottom of the dialog, after the message provided by the script.">
         Are you sure you want to leave this page?
@@ skipping 3049 matching lines @@
       <message name="IDS_STATUSBAR_BATTERY_IS_CHARGED" desc="In the power menu button, the battery is charged message.">
         Battery is charged
       </message>
       <message name="IDS_COMPACT_NAVBAR" desc="The menu item on the app menu to toggle compact navigation bar">
         Toggle Compact Navigation Bar
       </message>
     </if>
     </messages>
   </release>
 </grit>