Revert "[scenic] SessionMgr now uses eventpairs"

This reverts commit 3142417d8b8615c51887a9d9bc3281406809a1d1.

Reason for revert: Breaks mods being displayed in Ermine.

Original change's description:
> [scenic] SessionMgr now uses eventpairs
>
> TEST: set_root_view perspective; Ran SysUI
> SCN-897 #comment
> SCN-1033 #comment
>
> Change-Id: I18d57c41081912c8fcd2d6277854d1d401068399

MF-162 #done
TBR=mikejurka@google.com,thatguy@google.com,jaeheon@google.com,dworsham@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: I6333cf8170a523ed769377ffaf77fa482e293af7
diff --git a/bin/sessionmgr/sessionmgr_impl.cc b/bin/sessionmgr/sessionmgr_impl.cc
index 3ef496c..c64d75d 100644
--- a/bin/sessionmgr/sessionmgr_impl.cc
+++ b/bin/sessionmgr/sessionmgr_impl.cc
@@ -191,20 +191,6 @@
     fidl::InterfaceHandle<fuchsia::modular::internal::UserContext> user_context,
     fidl::InterfaceRequest<fuchsia::ui::viewsv1token::ViewOwner>
         view_owner_request) {
-  Initialize2(std::move(account), std::move(session_shell),
-              std::move(story_shell), std::move(ledger_token_manager),
-              std::move(agent_token_manager), std::move(user_context),
-              zx::eventpair(view_owner_request.TakeChannel().release()));
-}
-
-void SessionmgrImpl::Initialize2(
-    fuchsia::modular::auth::AccountPtr account,
-    fuchsia::modular::AppConfig session_shell,
-    fuchsia::modular::AppConfig story_shell,
-    fidl::InterfaceHandle<fuchsia::auth::TokenManager> ledger_token_manager,
-    fidl::InterfaceHandle<fuchsia::auth::TokenManager> agent_token_manager,
-    fidl::InterfaceHandle<fuchsia::modular::internal::UserContext> user_context,
-    zx::eventpair session_shell_view_token) {
   InitializeUser(std::move(account), std::move(agent_token_manager),
                  std::move(user_context));
   InitializeLedger(std::move(ledger_token_manager));
@@ -212,8 +198,9 @@
   InitializeMessageQueueManager();
   InitializeMaxwellAndModular(session_shell.url, std::move(story_shell));
   InitializeClipboard();
-  InitializeSessionShell(std::move(session_shell),
-                         std::move(session_shell_view_token));
+  InitializeSessionShell(
+      std::move(session_shell),
+      zx::eventpair(view_owner_request.TakeChannel().release()));
 
   ReportEvent(ModularEvent::BOOTED_TO_SESSIONMGR);
 }
@@ -719,14 +706,11 @@
     Logout();
   });
 
-  zx::eventpair view_token, view_holder_token;
-  if (zx::eventpair::create(0u, &view_token, &view_holder_token) != ZX_OK)
-    FXL_NOTREACHED() << "Failed to create view tokens";
-
-  fuchsia::ui::app::ViewProviderPtr view_provider;
+  fuchsia::ui::viewsv1token::ViewOwnerPtr view_owner;
+  fuchsia::ui::viewsv1::ViewProviderPtr view_provider;
   session_shell_app_->services().ConnectToService(view_provider.NewRequest());
-  view_provider->CreateView(std::move(view_token), nullptr, nullptr);
-  session_shell_view_host_->ConnectView(std::move(view_holder_token));
+  view_provider->CreateView(view_owner.NewRequest(), nullptr);
+  session_shell_view_host_->ConnectView(std::move(view_owner));
 
   fuchsia::modular::SessionShellPtr session_shell;
   session_shell_app_->services().ConnectToService(session_shell.NewRequest());
diff --git a/bin/sessionmgr/sessionmgr_impl.h b/bin/sessionmgr/sessionmgr_impl.h
index 989bee5..f1571ae 100644
--- a/bin/sessionmgr/sessionmgr_impl.h
+++ b/bin/sessionmgr/sessionmgr_impl.h
@@ -96,17 +96,6 @@
           view_owner_request) override;
 
   // |Sessionmgr|
-  void Initialize2(
-      fuchsia::modular::auth::AccountPtr account,
-      fuchsia::modular::AppConfig session_shell,
-      fuchsia::modular::AppConfig story_shell,
-      fidl::InterfaceHandle<fuchsia::auth::TokenManager> ledger_token_manager,
-      fidl::InterfaceHandle<fuchsia::auth::TokenManager> agent_token_manager,
-      fidl::InterfaceHandle<fuchsia::modular::internal::UserContext>
-          user_context,
-      zx::eventpair session_shell_view_token) override;
-
-  // |Sessionmgr|
   void SwapSessionShell(fuchsia::modular::AppConfig session_shell_config,
                         SwapSessionShellCallback callback) override;
 
diff --git a/public/fidl/fuchsia.modular.internal/sessionmgr.fidl b/public/fidl/fuchsia.modular.internal/sessionmgr.fidl
index 04cc63c..5a9f440 100644
--- a/public/fidl/fuchsia.modular.internal/sessionmgr.fidl
+++ b/public/fidl/fuchsia.modular.internal/sessionmgr.fidl
@@ -19,30 +19,21 @@
     // Launches a sessionmgr instance for a user identified by |user_id| and
     // specific TokenManager handles for ledger and agent_runner.
     // TODO(alhaad): Fold paramters into |UserContext|.
-    Initialize(fuchsia.modular.auth.Account? account,
-               fuchsia.modular.AppConfig session_shell,
-               fuchsia.modular.AppConfig story_shell,
-               fuchsia.auth.TokenManager? ledger_token_manager,
-               fuchsia.auth.TokenManager? agent_token_manager,
-               UserContext user_context,
-               request<fuchsia.ui.viewsv1token.ViewOwner>? view_owner);
+    1: Initialize(fuchsia.modular.auth.Account? account,
+                  fuchsia.modular.AppConfig session_shell,
+                  fuchsia.modular.AppConfig story_shell,
+                  fuchsia.auth.TokenManager? ledger_token_manager,
+                  fuchsia.auth.TokenManager? agent_token_manager,
+                  UserContext user_context,
+                  request<fuchsia.ui.viewsv1token.ViewOwner>? view_owner);
 
-    [Transitional]
-    Initialize2(fuchsia.modular.auth.Account? account,
-                fuchsia.modular.AppConfig session_shell,
-                fuchsia.modular.AppConfig story_shell,
-                fuchsia.auth.TokenManager? ledger_token_manager,
-                fuchsia.auth.TokenManager? agent_token_manager,
-                UserContext user_context,
-                handle<eventpair> session_shell_view_token);
-
-    SwapSessionShell(fuchsia.modular.AppConfig session_shell) -> ();
+    2: SwapSessionShell(fuchsia.modular.AppConfig session_shell) -> ();
 };
 
 // This interface is provided by basemgr to |Sessionmgr|.
 interface UserContext {
     // See detailed comments in SessionShellContext.Logout().
-    Logout();
+    1: Logout();
 
-    GetPresentation(request<fuchsia.ui.policy.Presentation> presentation);
+    2: GetPresentation(request<fuchsia.ui.policy.Presentation> presentation);
 };