Fixed the issue with multiple layers of folders and giving correct node.url to the new window object.

takeoff.js

@@ -0,0 +1,34 @@
+var marks = [];
+
+chrome.bookmarks.getTree(function(itemTree){
+    itemTree.forEach(function(item){
+        processNode(item);
+    });
+});
+
+function processNode(node) {
+	
+    // recursively process child nodes
+    if(node.children) {
+        node.children.forEach(function(child) {
+			processNode(child);
+        });
+    }
+
+    // print leaf nodes URLs to console
+    if(node.url) {
+		console.log(node.url);
+		var book = marks.push(node.url);
+    }
+}
+
+
+
+function setPage(windowObj) {
+	bookmark = marks[Math.floor(Math.random() * marks.length)];
+	chrome.tabs.getSelected(windowObj.windowId, function(tab) {
+		chrome.tabs.update(tab.id, {url: bookmark});
+	});
+}
+
+chrome.windows.getLastFocused(setPage);