Add a help bubble pointing to the omnibox when installing an extension with

chrome/app/generated_resources.grd

Index: chrome/app/generated_resources.grd
diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index 3653cd60c851e0f697a8a17818de11cde1c07c6b..0b47e633c124edccdf22cad58934497d75473a85 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -3711,6 +3711,9 @@ each locale. -->
       <message name="IDS_EXTENSION_INSTALLED_PAGE_ACTION_INFO" desc="Text displayed in the InfoBubble which explains that the UI of this extension is a Page Action icon which may appear for some pages.">
         This icon will be visible when the extension can act on the current page.
       </message>
+      <message name="IDS_EXTENSION_INSTALLED_OMNIBOX_KEYWORD_INFO" desc="Text displayed in the InfoBubble which explains that this extension has an keyword that can be used with the omnibox.">
+        To use this extension, type "<ph name="EXTENSION_KEYWORD">$1<ex>search</ex></ph>", then SPACE, then your search string.
+      </message>
 
       <message name="IDS_MANAGE_EXTENSIONS" desc="The 'Manage Extensions...' text in the context menu for when right-clicking on extension icons">
         Manage extensions...