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 dafef9093c2a54767f6b54dbecb369bbbd204355..a5f6fef1cf5504b3169256577bb321952bcc812f 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_controller.cc
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_controller.cc
@@ -359,6 +359,12 @@ ash::LauncherID ChromeLauncherController::GetLauncherIDForAppID(
   return 0;
 }
 
+std::string ChromeLauncherController::GetAppIDForLauncherID(
+    ash::LauncherID id) {
+  DCHECK(id_to_item_map_.find(id) != id_to_item_map_.end());
+  return id_to_item_map_[id].app_id;
+}
+
 void ChromeLauncherController::SetAppImage(const std::string& id,
                                            const gfx::ImageSkia& image) {
   // TODO: need to get this working for shortcuts.