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

chrome/browser/ui/views/location_bar/location_bar_view.h

Index: chrome/browser/ui/views/location_bar/location_bar_view.h
diff --git a/chrome/browser/ui/views/location_bar/location_bar_view.h b/chrome/browser/ui/views/location_bar/location_bar_view.h
index 50351c136b49a92055abaab6cf4b215eca5b6bd6..253c17efda6d61923363579485974cadb1de13b4 100644
--- a/chrome/browser/ui/views/location_bar/location_bar_view.h
+++ b/chrome/browser/ui/views/location_bar/location_bar_view.h
@@ -148,6 +148,10 @@ class LocationBarView : public LocationBar,
   // Shows the bookmark bubble.
   void ShowStarBubble(const GURL& url, bool newly_bookmarked);
 
+  // Returns the screen coordinates of the location entry (where the URL text
+  // appears, not where the icons are shown).
+  gfx::Point GetLocationEntryOrigin() const;
+
   // Sizing functions
   virtual gfx::Size GetPreferredSize();