Remove ash dependency on WebUILoginView::MoveFocusToSystemTray

LoginScreen::FocusLoginShelf() mojo API can be reused.

BUG=854346
TEST=trybot

Change-Id: Ide7dad98e1da57826d37d5dff4c3e269aee07c14
Reviewed-on: https://chromium-review.googlesource.com/c/1325689Reviewed-by: Jacob Dufault <jdufault@chromium.org>
Commit-Queue: Jun Mukai <mukai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606662}

ash/login/login_screen_controller.cc

@@ -495,7 +495,9 @@ void LoginScreenController::FocusLoginShelf(bool reverse) {
   Shelf* shelf = Shelf::ForWindow(Shell::Get()->GetPrimaryRootWindow());
   // Tell the focus direction to the status area or the shelf so they can focus
   // the correct child view.
-  if (reverse) {
+  if (reverse && !ShelfWidget::IsUsingViewsShelf()) {
+    if (Shell::GetPrimaryRootWindowController()->IsSystemTrayVisible())
+      return;
     shelf->GetStatusAreaWidget()
         ->status_area_widget_delegate()
         ->set_default_last_focusable_child(reverse);

chrome/browser/chromeos/login/ui/DEPS

@@ -11,18 +11,10 @@ specific_include_rules = {
   "input_events_blocker\.cc": [
     "+ash/shell.h",
   ],
-  # TODO(mash): Fix. https://crbug.com/854328
-  "login_display_host_common\.cc": [
-    "+ash/shell.h",
-  ],
   # TODO(mash): Fix. https://crbug.com/854346
   "webui_login_view.*": [
      "+ash/accelerators/accelerator_controller.h",
-     "+ash/focus_cycler.h",
      "+ash/public/cpp/ash_features.h",
-     "+ash/root_window_controller.h",
-     "+ash/shelf/shelf.h",
-     "+ash/shelf/shelf_widget.h",
      "+ash/shell.h",
      "+ash/system",
   ],

chrome/browser/chromeos/login/ui/login_display_host_common.cc

@@ -4,7 +4,6 @@
 
 #include "chrome/browser/chromeos/login/ui/login_display_host_common.h"
 
-#include "ash/shell.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/chromeos/login/app_launch_controller.h"

chrome/browser/chromeos/login/ui/webui_login_view.cc

@@ -7,14 +7,8 @@
 #include <memory>
 
 #include "ash/accelerators/accelerator_controller.h"
-#include "ash/focus_cycler.h"
 #include "ash/public/cpp/ash_features.h"
-#include "ash/root_window_controller.h"
-#include "ash/shelf/shelf.h"
-#include "ash/shelf/shelf_widget.h"
 #include "ash/shell.h"
-#include "ash/system/status_area_widget.h"
-#include "ash/system/status_area_widget_delegate.h"
 #include "ash/system/tray/system_tray_notifier.h"
 #include "base/bind.h"
 #include "base/callback.h"
@@ -39,6 +33,7 @@
 #include "chrome/browser/renderer_preferences_util.h"
 #include "chrome/browser/sessions/session_tab_helper.h"
 #include "chrome/browser/ui/ash/chrome_keyboard_controller_client.h"
+#include "chrome/browser/ui/ash/login_screen_client.h"
 #include "chrome/browser/ui/ash/system_tray_client.h"
 #include "chrome/browser/ui/autofill/chrome_autofill_client.h"
 #include "chrome/browser/ui/webui/chromeos/internet_detail_dialog.h"
@@ -558,38 +553,14 @@ void WebUILoginView::OnFocusLeavingSystemTray(bool reverse) {
 }
 
 bool WebUILoginView::MoveFocusToSystemTray(bool reverse) {
-  // Focus is accepted, but the Ash system tray is not available in Mash, so
-  // exit early. https://crbug.com/782072
-  if (features::IsMultiProcessMash())
-    return true;
-
-  // The focus should not move to the system tray if voice interaction OOOBE is
+  // The focus should not move to the system tray if voice interaction OOBE is
   // active.
   if (LoginDisplayHost::default_host() &&
       LoginDisplayHost::default_host()->IsVoiceInteractionOobe()) {
     return false;
   }
 
-  // If shift+tab is used (|reverse| is true) and views-based shelf is shown,
-  // focus goes to the shelf widget. If views-based shelf is disabled, focus
-  // goes to the system tray, because the web-UI shelf has already been
-  // traversed when we reach here.
-  ash::Shelf* shelf = ash::Shelf::ForWindow(GetWidget()->GetNativeWindow());
-  if (!reverse && ash::ShelfWidget::IsUsingViewsShelf()) {
-    shelf->shelf_widget()->set_default_last_focusable_child(reverse);
-    ash::Shell::Get()->focus_cycler()->FocusWidget(shelf->shelf_widget());
-    return true;
-  }
-
-  ash::RootWindowController* primary_controller =
-      ash::RootWindowController::ForWindow(GetWidget()->GetNativeWindow());
-  if (!primary_controller->IsSystemTrayVisible())
-    return false;
-
-  shelf->GetStatusAreaWidget()
-      ->status_area_widget_delegate()
-      ->set_default_last_focusable_child(reverse);
-  ash::Shell::Get()->focus_cycler()->FocusWidget(shelf->GetStatusAreaWidget());
+  LoginScreenClient::Get()->login_screen()->FocusLoginShelf(reverse);
   return true;
 }