Create a prominent omnibox UI element to add pages to the app launcher.

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 ccb0c07887434306899228a79a93b0317995e76f..9f890cb06aa370613f5ccfc9e1241085581ca037 100644
--- a/chrome/browser/ui/views/location_bar/location_bar_view.h
+++ b/chrome/browser/ui/views/location_bar/location_bar_view.h
@@ -30,6 +30,7 @@
 #include "ui/views/drag_controller.h"
 
 class ActionBoxButtonView;
+class AddToAppLauncherView;
 class CommandUpdater;
 class ContentSettingBubbleModelDelegate;
 class ContentSettingImageView;
@@ -495,6 +496,9 @@ class LocationBarView : public LocationBar,
   // The icon for Translate.
   TranslateIconView* translate_icon_view_;
 
+  // The view to add pages to the app launcher.
+  AddToAppLauncherView* add_to_app_launcher_view_;
+
   // The star.
   StarView* star_view_;