LibWeb: Notify the PageClient when the children of <title> change

Libraries/LibWeb/HTML/HTMLTitleElement.cpp

@@ -24,7 +24,9 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <LibWeb/DOM/Document.h>
 #include <LibWeb/HTML/HTMLTitleElement.h>
+#include <LibWeb/Page/Page.h>
 
 namespace Web::HTML {
 
@@ -37,4 +39,11 @@ HTMLTitleElement::~HTMLTitleElement()
 {
 }
 
+void HTMLTitleElement::children_changed()
+{
+    HTMLElement::children_changed();
+    if (auto* page = document().page())
+        page->client().page_did_change_title(document().title());
+}
+
 }