[gnome-shell] sessionMode: add a property to disable window manager menus

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 3b6fae582bfffbbb0de0b263c6cb33ef9e11218a
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Sat Jun 3 15:37:36 2017 -0700

    sessionMode: add a property to disable window manager menus
    
    We will use this to disable menus in the initial-setup session.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/569

 js/ui/sessionMode.js | 2 ++
 js/ui/windowMenu.js  | 3 +++
 2 files changed, 5 insertions(+)
---
diff --git a/js/ui/sessionMode.js b/js/ui/sessionMode.js
index 25aa75a3d..1f3e23b7a 100644
--- a/js/ui/sessionMode.js
+++ b/js/ui/sessionMode.js
@@ -25,6 +25,7 @@ const _modes = {
         hasWorkspaces: false,
         hasWindows: false,
         hasNotifications: false,
+        hasWmMenus: false,
         isLocked: false,
         isGreeter: false,
         isPrimary: false,
@@ -86,6 +87,7 @@ const _modes = {
         hasRunDialog: true,
         hasWorkspaces: true,
         hasWindows: true,
+        hasWmMenus: true,
         hasNotifications: true,
         isLocked: false,
         isPrimary: true,
diff --git a/js/ui/windowMenu.js b/js/ui/windowMenu.js
index 78b307db8..ed161765e 100644
--- a/js/ui/windowMenu.js
+++ b/js/ui/windowMenu.js
@@ -203,6 +203,9 @@ var WindowMenuManager = class {
     }
 
     showWindowMenuForWindow(window, type, rect) {
+        if (!Main.sessionMode.hasWmMenus)
+            return;
+
         if (type != Meta.WindowMenuType.WM)
             throw new Error('Unsupported window menu type');
         let menu = new WindowMenu(window, this._sourceActor);