Remove some pre-md code and assets.

ash/common/system/chromeos/session/tray_session_length_limit.cc

 // Copyright 2014 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/chromeos/session/tray_session_length_limit.h"
 
 #include <algorithm>
 #include <memory>
 #include <utility>
 
 #include "ash/common/system/system_notifier.h"
 #include "ash/common/system/tray/label_tray_view.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/tray/tray_constants.h"
 #include "ash/resources/grit/ash_resources.h"
+#include "ash/resources/vector_icons/vector_icons.h"
 #include "ash/shell.h"
 #include "ash/strings/grit/ash_strings.h"
 #include "base/logging.h"
 #include "base/strings/utf_string_conversions.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/l10n/time_format.h"
-#include "ui/base/resource/resource_bundle.h"
+#include "ui/gfx/paint_vector_icon.h"
 #include "ui/message_center/message_center.h"
 #include "ui/message_center/notification.h"
 #include "ui/views/view.h"
 
 namespace ash {
 namespace {
 
 // If the remaining session time falls below this threshold, the user should be
 // informed that the session is about to expire.
 const int kExpiringSoonThresholdInMinutes = 5;
@@ skipping 100 matching lines @@
     message_center::MessageCenter::Get()->RemoveNotification(
         kNotificationId, false /* by_user */);
   }
 
   // For LIMIT_NONE, there's nothing more to do.
   if (limit_state_ == LIMIT_NONE) {
     last_limit_state_ = limit_state_;
     return;
   }
 
-  ui::ResourceBundle& bundle = ui::ResourceBundle::GetSharedInstance();
   message_center::RichNotificationData data;
   data.should_make_spoken_feedback_for_popup_updates =
       (limit_state_ != last_limit_state_);
   std::unique_ptr<message_center::Notification> notification(
       new message_center::Notification(
           message_center::NOTIFICATION_TYPE_SIMPLE, kNotificationId,
           base::string16() /* title */,
           ComposeNotificationMessage() /* message */,
-          bundle.GetImageNamed(
-              IDR_AURA_UBER_TRAY_NOTIFICATION_SESSION_LENGTH_LIMIT),
+          gfx::Image(
+              gfx::CreateVectorIcon(kSystemMenuTimerIcon, kMenuIconColor)),
           base::string16() /* display_source */, GURL(),
           message_center::NotifierId(
               message_center::NotifierId::SYSTEM_COMPONENT,
               system_notifier::kNotifierSessionLengthTimeout),
           data, NULL /* delegate */));
   notification->SetSystemPriority();
   if (message_center->FindVisibleNotificationById(kNotificationId))
     message_center->UpdateNotification(kNotificationId,
                                        std::move(notification));
   else
@@ skipping 21 matching lines @@
 
 base::string16 TraySessionLengthLimit::ComposeTrayBubbleMessage() const {
   return l10n_util::GetStringFUTF16(
       IDS_ASH_STATUS_TRAY_BUBBLE_SESSION_LENGTH_LIMIT,
       ui::TimeFormat::Detailed(ui::TimeFormat::FORMAT_DURATION,
                                ui::TimeFormat::LENGTH_LONG, 10,
                                remaining_session_time_));
 }
 
 }  // namespace ash