Display "Restart to update" dialog to Chrome OS users.

ash/common/system/update/tray_update.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 "ash/common/system/update/tray_update.h"
 
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/metrics/user_metrics_action.h"
 #include "ash/common/system/tray/fixed_sized_image_view.h"
 #include "ash/common/system/tray/system_tray.h"
@@ skipping 98 matching lines @@
             : bundle.GetLocalizedString(IDS_ASH_STATUS_TRAY_UPDATE);
     label_ = TrayPopupUtils::CreateDefaultLabel();
     label_->SetText(label_text);
     SetAccessibleName(label_text);
     tri_view->AddView(TriView::Container::CENTER, label_);
 
     if (MaterialDesignController::IsSystemTrayMenuMaterial()) {
       UpdateStyle();
       SetInkDropMode(InkDropHostView::InkDropMode::ON);
     }
+
+    component_update_required_ = info.component_update_required;
   }
 
   ~UpdateView() override {}
 
  private:
   void UpdateStyle() {
     TrayPopupItemStyle style(GetNativeTheme(),
                              TrayPopupItemStyle::FontStyle::DEFAULT_VIEW_LABEL);
     style.SetupLabel(label_);
   }
 
   // Overridden from ActionableView.
   bool PerformAction(const ui::Event& event) override {
-    WmShell::Get()->system_tray_controller()->RequestRestartForUpdate();
+    WmShell::Get()->system_tray_controller()->RequestRestartForUpdate(
+        component_update_required_);
     WmShell::Get()->RecordUserMetricsAction(
         UMA_STATUS_AREA_OS_UPDATE_DEFAULT_SELECTED);
     CloseSystemBubble();
     return true;
   }
 
   void OnNativeThemeChanged(const ui::NativeTheme* theme) override {
     ActionableView::OnNativeThemeChanged(theme);
 
     if (!MaterialDesignController::IsSystemTrayMenuMaterial())
       return;
     UpdateStyle();
   }
 
   views::Label* label_;

[James Cook, 2016/11/30 23:01:41]

nit (if you keep this): either label_ = nullptr here or
component_update_required_(false) in constructor for consistency

+  bool component_update_required_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(UpdateView);
 };
 
 }  // namespace
 
 TrayUpdate::TrayUpdate(SystemTray* system_tray)
     : TrayImageItem(system_tray, IDR_AURA_UBER_TRAY_UPDATE, UMA_UPDATE) {
   WmShell::Get()->system_tray_notifier()->AddUpdateObserver(this);
 }
 
 TrayUpdate::~TrayUpdate() {
   WmShell::Get()->system_tray_notifier()->RemoveUpdateObserver(this);
 }
 
 bool TrayUpdate::GetInitialVisibility() {
   UpdateInfo info;
   WmShell::Get()->system_tray_delegate()->GetSystemUpdateInfo(&info);
   return info.update_required;
 }
 
 views::View* TrayUpdate::CreateDefaultView(LoginStatus status) {
   UpdateInfo info;
   WmShell::Get()->system_tray_delegate()->GetSystemUpdateInfo(&info);
-  return info.update_required ? new UpdateView(this, info) : nullptr;
+  return info.update_required || info.component_update_required
+             ? new UpdateView(this, info)
+             : nullptr;
 }
 
 void TrayUpdate::OnUpdateRecommended(const UpdateInfo& info) {
   if (MaterialDesignController::UseMaterialDesignSystemIcons())
     SetIconColor(IconColorForUpdateSeverity(info.severity, false));
   else
     SetImageFromResourceId(DecideResource(info.severity, false));
   tray_view()->SetVisible(true);
 }
 
 }  // namespace ash