Change the launcher to use AccessiblePaneView, and make the buttons focusable

ash/launcher/tabbed_launcher_button.cc

 // Copyright (c) 2012 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/launcher/tabbed_launcher_button.h"
 
 #include <algorithm>
 
 #include "ash/launcher/launcher_button_host.h"
 #include "grit/ui_resources.h"
@@ skipping 46 matching lines @@
                                  IDR_AURA_LAUNCHER_TABBED_BROWSER_1_HOT);
     bg_image_2_ = CreateImageSet(IDR_AURA_LAUNCHER_TABBED_BROWSER_2,
                                  IDR_AURA_LAUNCHER_TABBED_BROWSER_2_PUSHED,
                                  IDR_AURA_LAUNCHER_TABBED_BROWSER_2_HOT);
     bg_image_3_ = CreateImageSet(IDR_AURA_LAUNCHER_TABBED_BROWSER_3,
                                  IDR_AURA_LAUNCHER_TABBED_BROWSER_3_PUSHED,
                                  IDR_AURA_LAUNCHER_TABBED_BROWSER_3_HOT);
   }
   SetImageAlignment(views::ImageButton::ALIGN_CENTER,
                     views::ImageButton::ALIGN_MIDDLE);
+  set_focusable(true);
 }
 
 TabbedLauncherButton::~TabbedLauncherButton() {
 }
 
 void TabbedLauncherButton::PrepareForImageChange() {
   if (!show_image_ || (animation_.get() && animation_->is_animating()))
     return;
 
   // Pause for 500ms, then ease out for 200ms.
@@ skipping 92 matching lines @@
   ImageSet* set = new ImageSet;
   ResourceBundle& rb = ResourceBundle::GetSharedInstance();
   set->normal_image = new SkBitmap(*rb.GetImageNamed(normal_id).ToSkBitmap());
   set->pushed_image = new SkBitmap(*rb.GetImageNamed(pushed_id).ToSkBitmap());
   set->hot_image = new SkBitmap(*rb.GetImageNamed(hot_id).ToSkBitmap());
   return set;
 }
 
 }  // namespace internal
 }  // namespace ash