Update CrOS logout button for MD.

ui/views/controls/button/label_button.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 UI_VIEWS_CONTROLS_BUTTON_LABEL_BUTTON_H_
 #define UI_VIEWS_CONTROLS_BUTTON_LABEL_BUTTON_H_
 
 #include <memory>
 
 #include "base/compiler_specific.h"
@@ skipping 44 matching lines @@
   virtual void SetEnabledTextColors(SkColor color);
 
   // Sets drop shadows underneath the text.
   void SetTextShadows(const gfx::ShadowValues& shadows);
 
   // Sets whether subpixel rendering is used on the label.
   void SetTextSubpixelRenderingEnabled(bool enabled);
 
   // Gets or sets the font list used by this button.
   const gfx::FontList& GetFontList() const;
-  void SetFontList(const gfx::FontList& font_list);
+  // TODO(estade): make this function protected.
+  virtual void SetFontList(const gfx::FontList& font_list);
+
+  // Adjusts the font size up or down by the given amount.
+  virtual void AdjustFontSize(int font_size_delta);
 
   // Sets the elide behavior of this button.
   void SetElideBehavior(gfx::ElideBehavior elide_behavior);
 
   // Sets the horizontal alignment used for the button; reversed in RTL. The
   // optional image will lead the text, unless the button is right-aligned.
   void SetHorizontalAlignment(gfx::HorizontalAlignment alignment);
 
   // Call SetMinSize(gfx::Size()) to clear the monotonically increasing size.
   void SetMinSize(const gfx::Size& min_size);
@@ skipping 154 matching lines @@
   gfx::HorizontalAlignment horizontal_alignment_;
 
   std::unique_ptr<Painter> focus_painter_;
 
   DISALLOW_COPY_AND_ASSIGN(LabelButton);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_BUTTON_LABEL_BUTTON_H_