Fix pressing enter key crashes overview mode without a selection.

ash/wm/overview/window_selector.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/wm/overview/window_selector.h"
 
 #include <algorithm>
 
 #include "ash/accessibility_delegate.h"
 #include "ash/ash_switches.h"
@@ skipping 200 matching lines @@
     case ui::VKEY_DOWN:
       Move(WindowSelector::DOWN);
       break;
     case ui::VKEY_RIGHT:
       Move(WindowSelector::RIGHT);
       break;
     case ui::VKEY_LEFT:
       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.
       handled = false;
       break;
   }
   if (handled)
     event->SetHandled();
 }
 
@@ skipping 131 matching lines @@
     // root window, identify it and call Move() on it to initialize the
     // selection widget.
     // TODO(nsatragno): If there are more than two monitors, move between grids
     // in the requested direction.
     selected_grid_index_ = (selected_grid_index_ + 1) % grid_list_.size();
     grid_list_[selected_grid_index_]->Move(direction);
   }
 }
 
 }  // namespace ash