Added arrow key navigation to Overview Mode

ash/wm/overview/window_selector_item.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_item.h"
 
 #include "ash/screen_util.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/wm/overview/scoped_transform_overview_window.h"
@@ skipping 38 matching lines @@
   params.accept_events = false;
   params.visible_on_all_workspaces = true;
   widget->set_focus_on_creation(false);
   widget->Init(params);
   views::Label* label = new views::Label;
   label->SetEnabledColor(kLabelColor);
   label->SetBackgroundColor(kLabelBackground);
   label->SetShadowColors(kLabelShadow, kLabelShadow);
   label->SetShadowOffset(0, kVerticalShadowOffset);
   label->set_shadow_blur(kShadowBlur);
+  // TODO(dmassoni): Change to something more appropriate.
+  label->set_accessible_role(ui::AX_ROLE_BUTTON);
   ui::ResourceBundle& bundle = ui::ResourceBundle::GetSharedInstance();
   label->SetFontList(bundle.GetFontList(ui::ResourceBundle::BoldFont));
   label->SetText(title);
   views::BoxLayout* layout = new views::BoxLayout(views::BoxLayout::kVertical,
                                                   0,
                                                   kVerticalLabelPadding,
                                                   0);
   label->SetLayoutManager(layout);
   widget->SetContentsView(label);
   widget->Show();
@@ skipping 78 matching lines @@
           window_label_->GetNativeWindow()->layer()->GetAnimator());
       settings.SetPreemptionStrategy(
           ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
       settings.SetTransitionDuration(base::TimeDelta::FromMilliseconds(
           ScopedTransformOverviewWindow::kTransitionMilliseconds));
       window_label_->GetNativeWindow()->SetBounds(label_bounds);
     } else {
       window_label_->GetNativeWindow()->SetBounds(label_bounds);
     }
   }
-
 }
 
 }  // namespace ash