Pass embedding app identity through at embed time

mojo/services/public/cpp/view_manager/view_manager.h

Index: mojo/services/public/cpp/view_manager/view_manager.h
diff --git a/mojo/services/public/cpp/view_manager/view_manager.h b/mojo/services/public/cpp/view_manager/view_manager.h
index f02d38fcb94566992712f8d902400310632e8feb..36a1c4a7acae1c04fd02f9940ddcb54a713dc547 100644
--- a/mojo/services/public/cpp/view_manager/view_manager.h
+++ b/mojo/services/public/cpp/view_manager/view_manager.h
@@ -5,6 +5,7 @@
 #ifndef MOJO_SERVICES_PUBLIC_CPP_VIEW_MANAGER_VIEW_MANAGER_H_
 #define MOJO_SERVICES_PUBLIC_CPP_VIEW_MANAGER_VIEW_MANAGER_H_
 
+#include <string>
 #include <vector>
 
 #include "mojo/services/public/cpp/view_manager/view_manager_types.h"
@@ -22,6 +23,9 @@ class ViewManager {
   // Delegate is owned by the caller.
   static void Create(Application* application, ViewManagerDelegate* delegate);
 
+  // Returns the URL of the application that embedded this application.
+  virtual const std::string& GetEmbedderURL() const = 0;
+
   // Returns all root nodes known to this connection.
   virtual const std::vector<ViewTreeNode*>& GetRoots() const = 0;