Make the control buttons on a notification always show on non Chrome OS platform.

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 <stddef.h>
 
 #include "base/command_line.h"
 #include "base/macros.h"
@@ skipping 198 matching lines @@
 
   // Put together the different content and control views. Layering those allows
   // for proper layout logic and it also allows the close button and small
   // image to overlap the content as needed to provide large enough click and
   // touch areas (<http://crbug.com/168822> and <http://crbug.com/168856>).
   AddChildView(small_image_view_.get());
   CreateOrUpdateCloseButtonView(notification);
 
   SetEventTargeter(
       std::unique_ptr<views::ViewTargeter>(new views::ViewTargeter(this)));
+  set_notify_enter_exit_on_child(true);
 }
 
 NotificationView::~NotificationView() {
 }
 
 gfx::Size NotificationView::CalculatePreferredSize() const {
   int top_width = top_view_->GetPreferredSize().width() +
                   icon_view_->GetPreferredSize().width();
   int bottom_width = bottom_view_->GetPreferredSize().width();
   int preferred_width = std::max(top_width, bottom_width) + GetInsets().width();
@@ skipping 473 matching lines @@
         IDS_MESSAGE_CENTER_CLOSE_NOTIFICATION_BUTTON_TOOLTIP));
     close_button_->set_owned_by_client();
     AddChildView(close_button_.get());
     UpdateControlButtonsVisibility();
   } else if (notification.pinned() && close_button_) {
     close_button_.reset();
   }
 }
 
 void NotificationView::UpdateControlButtonsVisibility() {
+#if defined(OS_CHROMEOS)
+  // On Chrome OS, the settings button and the close button are shown only when
+  // the mouse is hovering on the notification.
   const bool target_visibility =
       IsMouseHovered() || HasFocus() ||
-      (close_button_ && close_button_->HasFocus()) ||
-      (settings_button_view_ && settings_button_view_->HasFocus());
+      (close_button_ &&
+       (close_button_->HasFocus() || close_button_->IsMouseHovered())) ||
+      (settings_button_view_ && (settings_button_view_->HasFocus() ||
+                                 settings_button_view_->IsMouseHovered()));
+#else
+  // On non Chrome OS, the settings button and the close button are always
+  // shown.
+  const bool target_visibility = true;
+#endif
 
   if (close_button_) {
     if (target_visibility != close_button_->visible())
       close_button_->SetVisible(target_visibility);
   }
 
   if (settings_button_view_) {
     if (target_visibility != settings_button_view_->visible())
       settings_button_view_->SetVisible(target_visibility);
   }
@@ skipping 34 matching lines @@
 
   return message_line_limit;
 }
 
 int NotificationView::GetMessageHeight(int width, int limit) const {
   return message_view_ ?
          message_view_->GetSizeForWidthAndLines(width, limit).height() : 0;
 }
 
 }  // namespace message_center