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 4a05dc54ad770c5f509a2d7f8d72b072d73b54b8..6cc91ab8c1befcc9a81ad25c0561f2969e1513f8 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_;