Make notifications accessible by keyboard when opened by keyboard.

Bug: 637351
Test: manually verified as in the bug
Change-Id: I27c833a2a9514af9b105126d1db2d0adffe358c0
Reviewed-on: https://chromium-review.googlesource.com/1059369
Commit-Queue: Tatsuhisa Yamaguchi <yamaguchi@chromium.org>
Reviewed-by: Tetsui Ohkubo <tetsui@chromium.org>
Reviewed-by: Yoshiki Iguchi <yoshiki@chromium.org>
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561739}

ash/accelerators/accelerator_controller.cc

@@ -422,10 +422,12 @@ void HandleToggleMessageCenterBubble() {
   NotificationTray* notification_tray = status_area_widget->notification_tray();
   if (!notification_tray->visible())
     return;
-  if (notification_tray->IsMessageCenterVisible())
+  if (notification_tray->IsMessageCenterVisible()) {
     notification_tray->CloseBubble();
-  else
+  } else {
     notification_tray->ShowBubble(false /* show_by_click */);
+    notification_tray->ActivateBubble();
+  }
 }
 
 void HandleToggleSystemTrayBubble() {

ash/system/message_center/notification_tray.cc

@@ -649,6 +649,15 @@ void NotificationTray::ShowBubble(bool show_by_click) {
     message_center_ui_controller_->ShowMessageCenterBubble(show_by_click);
 }
 
+void NotificationTray::ActivateBubble() {
+  views::TrayBubbleView* bubble_view = GetBubbleView();
+  // If the bubble is in the process of closing, do not try to activate it.
+  if (bubble_view->GetWidget()->IsClosed())
+    return;
+  bubble_view->set_can_activate(true);
+  bubble_view->GetWidget()->Activate();
+}
+
 views::TrayBubbleView* NotificationTray::GetBubbleView() {
   return message_center_bubble_ ? message_center_bubble_->bubble_view()
                                 : nullptr;

ash/system/message_center/notification_tray.h

@@ -87,6 +87,9 @@ class ASH_EXPORT NotificationTray
   void HidePopups() override;
   bool ShowNotifierSettings() override;
 
+  // Activates the notification tray bubble.
+  void ActivateBubble();
+
   message_center::MessageCenter* message_center() const;
 
  private: