Enable keyboard navigation for Desktopcapture window selection dialog

chrome/browser/ui/views/desktop_media_picker_views.cc

Index: chrome/browser/ui/views/desktop_media_picker_views.cc
diff --git a/chrome/browser/ui/views/desktop_media_picker_views.cc b/chrome/browser/ui/views/desktop_media_picker_views.cc
index b2975b2b2309b25d1a1208e10f30ccd1bbb3a35c..d38501a0bf5978baff01c8dd749a999817570640 100644
--- a/chrome/browser/ui/views/desktop_media_picker_views.cc
+++ b/chrome/browser/ui/views/desktop_media_picker_views.cc
@@ -206,6 +206,7 @@ DesktopMediaListView::DesktopMediaListView(
       media_list_(media_list.Pass()),
       weak_factory_(this) {
   media_list_->SetThumbnailSize(gfx::Size(kThumbnailWidth, kThumbnailHeight));
+  SetFocusable(true);
 }
 
 DesktopMediaListView::~DesktopMediaListView() {}
@@ -495,6 +496,10 @@ bool DesktopMediaPickerDialogView::IsDialogButtonEnabled(
   return true;
 }
 
+views::View* DesktopMediaPickerDialogView::GetInitiallyFocusedView(){
+  return list_view_;
+}
+
 base::string16 DesktopMediaPickerDialogView::GetDialogButtonLabel(
     ui::DialogButton button) const {
   return l10n_util::GetStringUTF16(button == ui::DIALOG_BUTTON_OK ?
@@ -543,6 +548,11 @@ void DesktopMediaPickerDialogView::OnMediaListRowsChanged() {
   GetWidget()->CenterWindow(gfx::Size(widget_bound.width(), new_height));
 }
 
+DesktopMediaListView*
+DesktopMediaPickerDialogView::GetMediaListViewForTesting() const {
+  return list_view_;
+}
+
 DesktopMediaSourceView*
 DesktopMediaPickerDialogView::GetMediaSourceViewForTesting(int index) const {
   if (list_view_->child_count() <= index)