Detect removed files and reflect the state in chrome://downloads and the download shelf

chrome/browser/ui/gtk/download/download_shelf_gtk.cc

Index: chrome/browser/ui/gtk/download/download_shelf_gtk.cc
diff --git a/chrome/browser/ui/gtk/download/download_shelf_gtk.cc b/chrome/browser/ui/gtk/download/download_shelf_gtk.cc
index 81078350552ff946215a88c405315c37255b341e..bc61bfafadf704a90f8bce50d73d8e4cb4ede145 100644
--- a/chrome/browser/ui/gtk/download/download_shelf_gtk.cc
+++ b/chrome/browser/ui/gtk/download/download_shelf_gtk.cc
@@ -286,6 +286,10 @@ void DownloadShelfGtk::MaybeShowMoreDownloadItems() {
   gtk_widget_show_all(items_hbox_.get());
 }
 
+void DownloadShelfGtk::CheckForFilesRemoval() {
+  browser_->CheckForFilesRemoval();
+}
+
 void DownloadShelfGtk::OnButtonClick(GtkWidget* button) {
   if (button == close_button_->widget()) {
     Close();