Dismiss action in tab modal dialogs.

ui/views/window/dialog_client_view.cc

Index: ui/views/window/dialog_client_view.cc
diff --git a/ui/views/window/dialog_client_view.cc b/ui/views/window/dialog_client_view.cc
index abffb5abba0467cc74e29bcf2746373b40114878..92484ee073a619a9bf1dd7ca92a5fda4655bedf1 100644
--- a/ui/views/window/dialog_client_view.cc
+++ b/ui/views/window/dialog_client_view.cc
@@ -54,10 +54,11 @@ void DialogClientView::AcceptWindow() {
 }
 
 void DialogClientView::CancelWindow() {
-  // Call the standard Close handler, which checks with the delegate before
-  // proceeding. This checking _isn't_ done here, but in the WM_CLOSE handler,
-  // so that the close box on the window also shares this code path.
-  Close();
+  // Only notify the delegate once. See |notified_delegate_|'s comment.
+  if (!notified_delegate_ && GetDialogDelegate()->Cancel()) {
+    notified_delegate_ = true;
+    Close();
+  }
 }
 
 void DialogClientView::UpdateDialogButtons() {
@@ -108,16 +109,14 @@ bool DialogClientView::CanClose() {
   if (notified_delegate_)
     return true;
 
-  DialogDelegate* dialog = GetDialogDelegate();
-  int buttons = dialog->GetDialogButtons();
-  bool close = true;
-  if ((buttons & ui::DIALOG_BUTTON_CANCEL) ||
-      (buttons == ui::DIALOG_BUTTON_NONE))
-    close = dialog->Cancel();
-  else if (buttons & ui::DIALOG_BUTTON_OK)
-    close = dialog->Accept(true);
-  notified_delegate_ = close;
-  return close;
+  // The dialog is closing but no Accept or Cancel action has been performed
+  // before: it's a Dismiss action.
+  if (GetDialogDelegate()->Dismiss()) {
+    notified_delegate_ = true;
+    GetDialogDelegate()->OnClose();
+    return true;
+  }
+  return false;
 }
 
 DialogClientView* DialogClientView::AsDialogClientView() {