Revert "Apply system style to shortcut changed notification."

This reverts commit 745c2ad.

Reason for revert: breaks  Linux Chromium OS ASan LSan Tests (1)

https://uberchromegw.corp.google.com/i/chromium.memory/builders/Linux%20Chromium%20OS%20ASan%20LSan%20Tests%20%281%29/builds/23305

https://findit-for-me.appspot.com/waterfall/build-failure?url=https://build.chromium.org/p/chromium.memory/builders/Linux%20Chromium%20OS%20ASan%20LSan%20Tests%20%281%29/builds/23305

Original change's description:
> Apply system style to shortcut changed notification.
> 
> In new-style notification system notification has different style from
> other notifications such as web notifications.
> This CL makes following changes to shortcut changed notification.
> * New MD icon is added.
> * The notification title is added.
> 
> TEST=manually tested on chell device
> BUG=751024,758269
> 
> Change-Id: Ie1649d9c80d53e4d031ddd3b45b8a40efae7cef3
> Reviewed-on: https://chromium-review.googlesource.com/634774
> Commit-Queue: Tetsui Ohkubo <tetsui@chromium.org>
> Reviewed-by: James Cook <jamescook@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#497695}

TBR=jamescook@chromium.org,tetsui@chromium.org

Change-Id: Ib11ef6266c92757afe45863d752e08848936da36
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 751024, 758269
Reviewed-on: https://chromium-review.googlesource.com/636424
Reviewed-by: Henrik Andreasson <henrika@chromium.org>
Commit-Queue: Henrik Andreasson <henrika@chromium.org>
Cr-Commit-Position: refs/heads/master@{#497719}

ash/accelerators/accelerator_controller.cc

@@ -78,7 +78,6 @@ namespace {
 using base::UserMetricsAction;
 using chromeos::input_method::InputMethodManager;
 using message_center::Notification;
-using message_center::SystemNotificationWarningLevel;
 
 // Identifier for the high contrast toggle accelerator notification.
 const char kHighContrastToggleAccelNotificationId[] =
@@ -154,18 +153,16 @@ void ShowDeprecatedAcceleratorNotification(const char* const notification_id,
                                            int new_shortcut_id) {
   const base::string16 message =
       GetNotificationText(message_id, old_shortcut_id, new_shortcut_id);
-  std::unique_ptr<Notification> notification =
-      system_notifier::CreateSystemNotification(
-          message_center::NOTIFICATION_TYPE_SIMPLE, notification_id,
-          l10n_util::GetStringUTF16(IDS_DEPRECATED_SHORTCUT_TITLE), message,
-          Shell::Get()->shell_delegate()->GetDeprecatedAcceleratorImage(),
-          base::string16(), GURL(),
-          message_center::NotifierId(
-              message_center::NotifierId::SYSTEM_COMPONENT,
-              system_notifier::kNotifierDeprecatedAccelerator),
-          message_center::RichNotificationData(),
-          new DeprecatedAcceleratorNotificationDelegate,
-          kNotificationSettingsIcon, SystemNotificationWarningLevel::NORMAL);
+  std::unique_ptr<Notification> notification(new Notification(
+      message_center::NOTIFICATION_TYPE_SIMPLE, notification_id,
+      base::string16(), message,
+      Shell::Get()->shell_delegate()->GetDeprecatedAcceleratorImage(),
+      base::string16(), GURL(),
+      message_center::NotifierId(
+          message_center::NotifierId::SYSTEM_COMPONENT,
+          system_notifier::kNotifierDeprecatedAccelerator),
+      message_center::RichNotificationData(),
+      new DeprecatedAcceleratorNotificationDelegate));
   message_center::MessageCenter::Get()->AddNotification(
       std::move(notification));
 }

ash/ash_strings.grd

@@ -1066,9 +1066,6 @@ This file contains the strings for ash.
       <message name="IDS_DEPRECATED_TOGGLE_HIGH_CONTRAST_MSG" desc="Notification message to tell users about the deprecation of Search+Shift+H shortcut to toggle the high contrast display mode.">
         The shortcut to toggle High Contrast Mode has changed. Please use <ph name="NEW_SHORTCUT">$1<ex>Ctrl+Search+H</ex></ph> instead of <ph name="OLD_SHORTCUT">$2<ex>Search+Shift+H</ex></ph>.
       </message>
-      <message name="IDS_DEPRECATED_SHORTCUT_TITLE" desc="Notification title to tell users that the keyboard accelerator is deprecated.">
-        Shortcut change
-      </message>
 
       <!-- Notification that an accelerator was pressed, so the user knows how to toggle it back -->
       <message name="IDS_HIGH_CONTRAST_ACCEL_MSG"

ash/resources/vector_icons/BUILD.gn

@@ -77,7 +77,6 @@ aggregate_vector_icons("ash_vector_icons") {
     "notification_feedback_button.1x.icon",
     "notification_feedback_button.icon",
     "notification_low_power_battery.icon",
-    "notification_settings.icon",
     "palette_action_capture_region.1x.icon",
     "palette_action_capture_region.icon",
     "palette_action_capture_screen.1x.icon",