Simplify layout of tray items and fix spacing for MD.

ash/common/system/tray/tray_item_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 ASH_COMMON_SYSTEM_TRAY_TRAY_ITEM_VIEW_H_
 #define ASH_COMMON_SYSTEM_TRAY_TRAY_ITEM_VIEW_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
@@ skipping 35 matching lines @@
   // Overridden from views::View.
   void SetVisible(bool visible) override;
   gfx::Size GetPreferredSize() const override;
   int GetHeightForWidth(int width) const override;
 
  protected:
   // Makes sure the widget relayouts after the size/visibility of the view
   // changes.
   void ApplyChange();
 
-  // This should return the desired size of the view. For most views, this
-  // returns GetPreferredSize. But since this class overrides GetPreferredSize
-  // for animation purposes, we allow a different way to get this size, and do
-  // not allow GetPreferredSize to be overridden.
-  virtual gfx::Size DesiredSize() const;
-
   // The default animation duration is 200ms. But each view can customize this.
   virtual int GetAnimationDurationMS();
 
  private:
   // Overridden from views::View.
   void ChildPreferredSizeChanged(View* child) override;
 
   // Overridden from gfx::AnimationDelegate.
   void AnimationProgressed(const gfx::Animation* animation) override;
   void AnimationEnded(const gfx::Animation* animation) override;
   void AnimationCanceled(const gfx::Animation* animation) override;
 
   SystemTrayItem* owner_;
   std::unique_ptr<gfx::SlideAnimation> animation_;
   views::Label* label_;
   views::ImageView* image_view_;
 
   DISALLOW_COPY_AND_ASSIGN(TrayItemView);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_TRAY_TRAY_ITEM_VIEW_H_