Remove last vestigial uses of "update needed" png assets.

chrome/browser/ui/views/critical_notification_bubble_view.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_VIEWS_CRITICAL_NOTIFICATION_BUBBLE_VIEW_H_
 #define CHROME_BROWSER_UI_VIEWS_CRITICAL_NOTIFICATION_BUBBLE_VIEW_H_
 
 #include "base/macros.h"
 #include "base/timer/timer.h"
 #include "ui/views/bubble/bubble_dialog_delegate.h"
 
 class CriticalNotificationBubbleView : public views::BubbleDialogDelegateView {
  public:
   explicit CriticalNotificationBubbleView(views::View* anchor_view);
   ~CriticalNotificationBubbleView() override;
 
   // views::BubbleDialogDelegateView overrides:
   base::string16 GetWindowTitle() const override;
-  gfx::ImageSkia GetWindowIcon() override;
-  bool ShouldShowWindowIcon() const override;
   void WindowClosing() override;
   bool Cancel() override;
   bool Accept() override;
   void Init() override;
   base::string16 GetDialogButtonLabel(ui::DialogButton button) const override;
   void GetAccessibleNodeData(ui::AXNodeData* node_data) override;
   void ViewHierarchyChanged(
       const ViewHierarchyChangedDetails& details) override;
 
  private:
   // Helper function to calculate the remaining time (in seconds) until
   // spontaneous reboot.
   int GetRemainingTime() const;
 
   // Called when the timer fires each time the clock ticks.
   void OnCountdown();
 
   // A timer to refresh the bubble to show new countdown value.
   base::RepeatingTimer refresh_timer_;
 
   // When the bubble was created.
   base::TimeTicks bubble_created_;
 
   DISALLOW_COPY_AND_ASSIGN(CriticalNotificationBubbleView);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_CRITICAL_NOTIFICATION_BUBBLE_VIEW_H_