Give platform apps control over launcher right-click context menu.

chrome/browser/ui/ash/launcher/chrome_launcher_controller.cc

Index: chrome/browser/ui/ash/launcher/chrome_launcher_controller.cc
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_controller.cc b/chrome/browser/ui/ash/launcher/chrome_launcher_controller.cc
index db97d8b5e76936eda7682006b63950ef0c46d6e3..1043827f64edc2c07dc75cf2c9278cfcd7e2d1fc 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_controller.cc
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_controller.cc
@@ -404,6 +404,13 @@ ash::LauncherID ChromeLauncherController::GetLauncherIDForAppID(
   return 0;
 }
 
+std::string ChromeLauncherController::GetAppIDForLauncherID(
+    ash::LauncherID id) {
+  DCHECK(id_to_item_controller_map_.find(id) !=
+      id_to_item_controller_map_.end());
+  return id_to_item_controller_map_[id]->app_id();
+}
+
 void ChromeLauncherController::SetAppImage(const std::string& id,
                                            const gfx::ImageSkia& image) {
   // TODO: need to get this working for shortcuts.