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

ash/launcher/launcher_view.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/launcher_view.h"
 
 #include "ash/launcher/app_launcher_button.h"
 #include "ash/launcher/launcher_model.h"
 #include "ash/launcher/launcher_window_cycler.h"
 #include "ash/launcher/tabbed_launcher_button.h"
@@ skipping 192 matching lines @@
 
   const LauncherItems& items(model_->items());
   for (LauncherItems::const_iterator i = items.begin(); i != items.end(); ++i) {
     views::View* child = CreateViewForItem(*i);
     child->SetPaintToLayer(true);
     view_model_->Add(child, static_cast<int>(i - items.begin()));
     AddChildView(child);
   }
 
   overflow_button_ = new views::ImageButton(this);
+  overflow_button_->set_focusable(true);
   overflow_button_->SetImage(
       views::CustomButton::BS_NORMAL,
       rb.GetImageNamed(IDR_AURA_LAUNCHER_OVERFLOW).ToSkBitmap());
   overflow_button_->SetImage(
       views::CustomButton::BS_HOT,
       rb.GetImageNamed(IDR_AURA_LAUNCHER_OVERFLOW_HOT).ToSkBitmap());
   overflow_button_->SetImage(
       views::CustomButton::BS_PUSHED,
       rb.GetImageNamed(IDR_AURA_LAUNCHER_OVERFLOW_PUSHED).ToSkBitmap());
   ConfigureChildView(overflow_button_);
@@ skipping 414 matching lines @@
       cycler_->Cycle();
       break;
 
     default:
       NOTREACHED();
   }
 }
 
 }  // namespace internal
 }  // namespace ash