Ladybird: Close inspector and JS console when tab closes

Keeping these around can lead to use-after-frees and crashes.

Ladybird/WebContentView.cpp

@@ -77,7 +77,7 @@ WebContentView::WebContentView(StringView webdriver_content_ipc_path)
 
 WebContentView::~WebContentView()
 {
-    clear_inspector_callbacks();
+    close_sub_widgets();
 }
 
 void WebContentView::load(AK::URL const& url)
@@ -515,10 +515,14 @@ void WebContentView::ensure_inspector_widget()
     };
 }
 
-void WebContentView::clear_inspector_callbacks()
+void WebContentView::close_sub_widgets()
 {
-    if (m_inspector_widget)
-        m_inspector_widget->on_close = nullptr;
+    auto close_widget_window = [](auto* widget) {
+        if (widget)
+            widget->close();
+    };
+    close_widget_window(m_console_widget);
+    close_widget_window(m_inspector_widget);
 }
 
 bool WebContentView::is_inspector_open() const

Ladybird/WebContentView.h

@@ -192,7 +192,7 @@ private:
     bool is_inspector_open() const;
     void inspect_dom_tree();
     void clear_inspected_dom_node();
-    void clear_inspector_callbacks();
+    void close_sub_widgets();
     ErrorOr<Ladybird::DOMNodeProperties> inspect_dom_node(i32 node_id, Optional<Web::CSS::Selector::PseudoElement> pseudo_element);
 
     qreal m_inverse_pixel_scaling_ratio { 1.0 };