SceneManager invokes resize method on all Systems.

src/scene/SceneManager.js

@@ -365,6 +365,26 @@ var SceneManager = new Class({
         }
     },
 
+    /**
+     * [description]
+     *
+     * @method Phaser.Scenes.SceneManager#resize
+     * @since 3.2.0
+     *
+     * @param {number} width - The new width of the game.
+     * @param {number} height - The new height of the game.
+     */
+    resize: function (width, height)
+    {
+        //  Loop through the scenes in forward order
+        for (var i = 0; i < this.scenes.length; i++)
+        {
+            var sys = this.scenes[i].sys;
+
+            sys.resize(width, height);
+        }
+    },
+
     /**
      * [description]
      *