Fix pressing enter key crashes overview mode without a selection.

ash/wm/overview/window_selector.cc

Index: ash/wm/overview/window_selector.cc
diff --git a/ash/wm/overview/window_selector.cc b/ash/wm/overview/window_selector.cc
index 593df59c90ee8f3cb18a5b5baa01c0e1b8a923b2..a5a1ce9fc65a5b7a60c1034b003fa5e261a6ed08 100644
--- a/ash/wm/overview/window_selector.cc
+++ b/ash/wm/overview/window_selector.cc
@@ -218,9 +218,10 @@ void WindowSelector::OnKeyEvent(ui::KeyEvent* event) {
       Move(WindowSelector::LEFT);
       break;
     case ui::VKEY_RETURN:
-      wm::GetWindowState(
-          grid_list_[selected_grid_index_]->
-              SelectedWindow()->SelectionWindow())->Activate();
+      if (grid_list_[selected_grid_index_]->is_selecting()) {

[tdanderson, 2014/06/06 21:15:17]

A short comment would be nice to say something like "ignore if no item is
selected"

[Nina, 2014/06/06 21:44:32]

Done.

+        wm::GetWindowState(grid_list_[selected_grid_index_]->
+                           SelectedWindow()->SelectionWindow())->Activate();
+      }

[tdanderson, 2014/06/06 21:15:17]

I think you will want to set handled = false; in the case where we're just
ignoring the VKEY_RETURN keypress.

[Nina, 2014/06/06 21:44:32]

Done.

       break;
     default:
       // Not a key we are interested in.