Add multiple selection support to chooser on desktops

chrome/browser/ui/views/chooser_content_view.cc

Index: chrome/browser/ui/views/chooser_content_view.cc
diff --git a/chrome/browser/ui/views/chooser_content_view.cc b/chrome/browser/ui/views/chooser_content_view.cc
index 35b450673e9fd6e56ef458953ebd002ed8ac7001..ee45a6817f5f8ee6f5cdbc365c86c64472c752d3 100644
--- a/chrome/browser/ui/views/chooser_content_view.cc
+++ b/chrome/browser/ui/views/chooser_content_view.cc
@@ -64,7 +64,7 @@ ChooserContentView::ChooserContentView(
       this, table_columns,
       chooser_controller_->ShouldShowIconBeforeText() ? views::ICON_AND_TEXT
                                                       : views::TEXT_ONLY,
-      true /* single_selection */);
+      !chooser_controller_->AllowMultipleSelection() /* single_selection */);
   table_view_->set_select_on_remove(false);
   table_view_->SetObserver(table_view_observer);
   table_view_->SetEnabled(chooser_controller_->NumOptions() > 0);
@@ -285,7 +285,8 @@ bool ChooserContentView::IsDialogButtonEnabled(ui::DialogButton button) const {
 }
 
 void ChooserContentView::Accept() {
-  chooser_controller_->Select(table_view_->selection_model().active());
+  for (int index : table_view_->selection_model().selected_indices())
+    chooser_controller_->Select(index);

[sky, 2016/11/22 04:37:35]

Isn't Select() a one time type call? I would expect you to pass it all the
selected indices, not just one.

[juncai, 2016/11/22 19:07:00]

Done.

 }
 
 void ChooserContentView::Cancel() {