Give up focus if the focused view becomes unfocusable

ui/message_center/views/notification_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 "ui/message_center/views/notification_view.h"
 
 #include "base/command_line.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "grit/ui_resources.h"
@@ skipping 326 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(NotificationButton);
 };
 
 NotificationButton::NotificationButton(views::ButtonListener* listener)
     : views::CustomButton(listener),
       icon_(NULL),
       title_(NULL),
       focus_painter_(views::Painter::CreateSolidFocusPainter(
                          message_center::kFocusBorderColor,
                          gfx::Insets(1, 2, 2, 2))) {
-  set_focusable(true);
+  SetFocusable(true);
   set_request_focus_on_press(false);
   set_notify_enter_exit_on_child(true);
   SetLayoutManager(
       new views::BoxLayout(views::BoxLayout::kHorizontal,
                            message_center::kButtonHorizontalPadding,
                            kButtonVecticalPadding,
                            message_center::kButtonIconToTitlePadding));
 }
 
 NotificationButton::~NotificationButton() {
@@ skipping 493 matching lines @@
   return message_view_ ?
          message_view_->GetLinesForWidthAndLimit(width, limit) : 0;
 }
 
 int NotificationView::GetMessageHeight(int width, int limit) {
   return message_view_ ?
          message_view_->GetSizeForWidthAndLines(width, limit).height() : 0;
 }
 
 }  // namespace message_center