Firefox overlay is seen opened even if Import Overlay is Cancelled.

chrome/browser/ui/views/importer/import_lock_dialog_view.cc

Index: chrome/browser/ui/views/importer/import_lock_dialog_view.cc
diff --git a/chrome/browser/ui/views/importer/import_lock_dialog_view.cc b/chrome/browser/ui/views/importer/import_lock_dialog_view.cc
index 71392b5908635fdeeced6d4f8fab2bd1cf316843..ccaf1032d6af26ecad53dbe0337c6de17b0fa039 100644
--- a/chrome/browser/ui/views/importer/import_lock_dialog_view.cc
+++ b/chrome/browser/ui/views/importer/import_lock_dialog_view.cc
@@ -22,6 +22,14 @@
 
 using base::UserMetricsAction;
 
+namespace {
+
+// A reference to the currently active widget backing the
+// import lock dialog, or null if the dialog is not open.
+static views::Widget* g_widget = nullptr;
+
+}
+
 namespace importer {
 
 void ShowImportLockDialog(gfx::NativeWindow parent,
@@ -30,13 +38,25 @@ void ShowImportLockDialog(gfx::NativeWindow parent,
   base::RecordAction(UserMetricsAction("ImportLockDialogView_Shown"));
 }
 
+void HideImportLockDialog() {
+  ImportLockDialogView::Hide();
+}
+
 }  // namespace importer
 
 // static
 void ImportLockDialogView::Show(gfx::NativeWindow parent,
                                 const base::Callback<void(bool)>& callback) {
-  views::DialogDelegate::CreateDialogWidget(
-      new ImportLockDialogView(callback), NULL, NULL)->Show();
+  ImportLockDialogView* dialog_view = new ImportLockDialogView(callback);
+  g_widget = views::DialogDelegate::CreateDialogWidget(dialog_view, NULL, NULL);
+  g_widget->AddObserver(dialog_view);
+  g_widget->Show();
+}
+
+// static
+void ImportLockDialogView::Hide() {
+  if (g_widget)
+    g_widget->Close();
 }
 
 ImportLockDialogView::ImportLockDialogView(
@@ -53,6 +73,12 @@ ImportLockDialogView::ImportLockDialogView(
 ImportLockDialogView::~ImportLockDialogView() {
 }
 
+void ImportLockDialogView::OnWidgetDestroying(views::Widget* widget) {
+  DCHECK_EQ(widget, g_widget);
+  g_widget = nullptr;
+  widget->RemoveObserver(this);
+}
+
 gfx::Size ImportLockDialogView::GetPreferredSize() const {
   return gfx::Size(views::Widget::GetLocalizedContentsSize(
       IDS_IMPORTLOCK_DIALOG_WIDTH_CHARS,