Add rollback icon for rollback notification

Add a new rollback icon (vertically flipped update icon) and use it in
the rollback notification.

Screenshot: https://screenshot.googleplex.com/UebqEykm9P7.png

Bug: 863088
Change-Id: I45dea5daac43469349a0cccd166a6338532ce55f
Reviewed-on: https://chromium-review.googlesource.com/1145071Reviewed-by: Jenny Zhang <jennyz@chromium.org>
Reviewed-by: Evan Stade <estade@chromium.org>
Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Commit-Queue: Marton Hunyady <hunyadym@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577023}

ash/resources/vector_icons/BUILD.gn

@@ -142,6 +142,7 @@ aggregate_vector_icons("ash_vector_icons") {
     "system_menu_mouse.icon",
     "system_menu_phone.icon",
     "system_menu_power.icon",
+    "system_menu_rollback.icon",
     "system_menu_rotation_lock_auto.icon",
     "system_menu_rotation_lock_landscape.icon",
     "system_menu_rotation_lock_portrait.icon",

ash/resources/vector_icons/system_menu_rollback.icon

+// Copyright 2018 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.
+
+CANVAS_DIMENSIONS, 40,
+MOVE_TO, 20, 36,
+R_CUBIC_TO, 8.84f, 0, 16, -7.16f, 16, -16,
+CUBIC_TO_SHORTHAND, 28.84f, 4, 20, 4,
+CUBIC_TO_SHORTHAND, 4, 11.16f, 4, 20,
+R_CUBIC_TO, 0, 8.84f, 7.16f, 16, 16, 16,
+CLOSE,
+R_MOVE_TO, -4, -25,
+R_H_LINE_TO, 8,
+R_V_LINE_TO, 6,
+R_H_LINE_TO, 6,
+LINE_TO, 20, 29,
+LINE_TO, 10, 17,
+R_H_LINE_TO, 6,
+R_V_LINE_TO, -6,
+CLOSE
+
+CANVAS_DIMENSIONS, 20,
+MOVE_TO, 10, 18,
+R_CUBIC_TO, 4.42f, 0, 8, -3.58f, 8, -8,
+R_CUBIC_TO, 0, -4.42f, -3.58f, -8, -8, -8,
+R_CUBIC_TO, -4.42f, 0, -8, 3.58f, -8, 8,
+R_CUBIC_TO, 0, 4.42f, 3.58f, 8, 8, 8,
+CLOSE,
+R_MOVE_TO, -2, -12,
+R_H_LINE_TO, 4,
+R_V_LINE_TO, 3,
+R_H_LINE_TO, 3,
+R_LINE_TO, -5, 6,
+R_LINE_TO, -5, -6,
+R_H_LINE_TO, 3,
+R_V_LINE_TO, -3,
+CLOSE

ash/system/update/update_notification_controller.cc

@@ -61,7 +61,8 @@ void UpdateNotificationController::OnUpdateAvailable() {
               base::BindRepeating(
                   &UpdateNotificationController::HandleNotificationClick,
                   weak_ptr_factory_.GetWeakPtr())),
-          kSystemMenuUpdateIcon, warning_level);
+          model_->rollback() ? kSystemMenuRollbackIcon : kSystemMenuUpdateIcon,
+          warning_level);
   notification->set_pinned(true);
 
   if (model_->update_required()) {