[scenic] Convert session_shell APIs to ViewToken

We consume some SDK clients as prebuilts, so they must implement the new
API before we call into it.

Tested: No behavior changed; modular_tests, started story in sysUI
SCN-1018 #comment
SCN-1291 #comment

Change-Id: Ifb8797b81c12c7ae293e295c1960e02ee3be1168

sdk/fidl/fuchsia.modular/fuchsia.modular.api

@@ -31,7 +31,7 @@
   "fidl/fuchsia.modular/module/module_state.fidl": "200892e14d9a6f3f1b46473477a02b99",
   "fidl/fuchsia.modular/module_resolver/module_resolver.fidl": "e6837b2e15ce3a7a1c899e02110b933d",
   "fidl/fuchsia.modular/session/focus.fidl": "7787b6c08cacd6c981d729c952f12f17",
-  "fidl/fuchsia.modular/session/session_shell.fidl": "8c9a5c08c1ff04ca3c8f3dcd61d01cfc",
+  "fidl/fuchsia.modular/session/session_shell.fidl": "682dd1fef2f72d694569f26e21cd9582",
   "fidl/fuchsia.modular/story/create_link.fidl": "a3e1da920eb02637478b914c2009bf90",
   "fidl/fuchsia.modular/story/create_module_parameter_map.fidl": "79bf5bdf04655966584b72ff0b1b3066",
   "fidl/fuchsia.modular/story/link.fidl": "5a0130509caadb5e6263ae76adbccd50",

sdk/fidl/fuchsia.modular/session/session_shell.fidl

@@ -7,6 +7,7 @@ library fuchsia.modular;
 using fuchsia.modular.auth;
 using fuchsia.speech;
 using fuchsia.ui.policy;
+using fuchsia.ui.views;
 using fuchsia.ui.viewsv1token;
 
 // This interface is implemented by a session shell and is used by the
@@ -16,7 +17,11 @@ using fuchsia.ui.viewsv1token;
 protocol SessionShell {
     // Displays the given story view. The story this view belongs to is
     // identified by |view_id.story_id|.
+    // DEPRECATED.  For transitional purposes only.
+    [Transitional]
     AttachView(ViewIdentifier view_id, fuchsia.ui.viewsv1token.ViewOwner view_owner);
+    [Transitional]
+    AttachView2(ViewIdentifier view_id, fuchsia.ui.views.ViewHolderToken view_holder_token);
 
     // Instructs the session shell to detach the view identified by |view_id|
     // that was previously provided by AttachView() from the UI of the session
@@ -41,6 +46,7 @@ protocol SessionShell {
 // field match those used in the |StoryProvider| interface, allowing
 // identification of the same story across interfaces.
 //
+
 // This is a struct rather than a naked string to allow for future evolution of
 // the identifier without changing the |SessionShell| API itself.
 struct ViewIdentifier {
@@ -75,6 +81,7 @@ protocol SessionShellContext {
 // Session shell provides this service to the framework which may plumb it to
 // different subscribers, such as story shell and intelligence provider.
 //
+
 // EXPERIMENTAL Service that allows consumers of a given story to get a
 // connection to a Presentation, and visual state services provided by the user
 // shell. This allows story shell implementations to coordinate event and focus