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

chrome/app/generated_resources.grd

Index: chrome/app/generated_resources.grd
===================================================================
--- chrome/app/generated_resources.grd	(revision 30970)
+++ chrome/app/generated_resources.grd	(working copy)
@@ -2751,19 +2751,31 @@
       </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>