Signin screen and locked screen status area focus advancing

ash/common/system/status_area_widget.cc

Index: ash/common/system/status_area_widget.cc
diff --git a/ash/common/system/status_area_widget.cc b/ash/common/system/status_area_widget.cc
index f9b41edbe1e24430e49b800b50c7fa85ac6d4f01..7d1ded8bd5612176ac9f5e8476902b4d6e995266 100644
--- a/ash/common/system/status_area_widget.cc
+++ b/ash/common/system/status_area_widget.cc
@@ -11,6 +11,7 @@
 #include "ash/common/system/status_area_widget_delegate.h"
 #include "ash/common/system/tray/system_tray.h"
 #include "ash/common/system/tray/system_tray_delegate.h"
+#include "ash/common/system/tray/system_tray_notifier.h"
 #include "ash/common/system/web_notification/web_notification_tray.h"
 #include "ash/common/wm_lookup.h"
 #include "ash/common/wm_root_window_controller.h"
@@ -18,6 +19,7 @@
 #include "ash/common/wm_window.h"
 #include "base/i18n/time_formatting.h"
 #include "ui/native_theme/native_theme_dark_aura.h"
+#include "ui/views/focus/focus_manager.h"
 
 #if defined(OS_CHROMEOS)
 #include "ash/common/system/chromeos/ime_menu/ime_menu_tray.h"
@@ -220,6 +222,11 @@ void StatusAreaWidget::OnNativeWidgetActivationChanged(bool active) {
     status_area_widget_delegate_->SetPaneFocusAndFocusDefault();
 }
 
+void StatusAreaWidget::OnKeyEvent(ui::KeyEvent* event) {
+  HandleFocusKeyEvent(event);
+  Widget::OnKeyEvent(event);

[xiyuan, 2016/09/12 18:19:09]

nit: Skip if event->handled() is true.

+}
+
 void StatusAreaWidget::UpdateShelfItemBackground(int alpha) {
   web_notification_tray_->UpdateShelfItemBackground(alpha);
   system_tray_->UpdateShelfItemBackground(alpha);
@@ -300,4 +307,26 @@ void StatusAreaWidget::AddOverviewButtonTray() {
   status_area_widget_delegate_->AddTray(overview_button_tray_);
 }
 
+void StatusAreaWidget::HandleFocusKeyEvent(ui::KeyEvent* event) {
+  WmShell* wm_shell = WmShell::Get();
+  LoginStatus status = wm_shell->system_tray_delegate()->GetUserLoginStatus();
+  bool is_tab_pressed = event->type() == ui::ET_KEY_PRESSED &&
+                        views::FocusManager::IsTabTraversalKeyEvent(*event);
+  views::FocusManager* focus_manager = GetFocusManager();
+  if ((status != LoginStatus::NOT_LOGGED_IN && status != LoginStatus::LOCKED) ||
+      !is_tab_pressed || !focus_manager) {
+    return;
+  }
+
+  bool reverse = event->IsShiftDown();
+  views::View* next_focusable_view = focus_manager->GetNextFocusableView(
+      focus_manager->GetFocusedView(), nullptr, reverse, false);
+  if (system_tray_ && system_tray_->visible() &&
+      system_tray_->Contains(next_focusable_view)) {
+    wm_shell->system_tray_notifier()->NotifyWillReturnFocusToWebContents(
+        reverse);
+    event->SetHandled();
+  }
+}
+
 }  // namespace ash