Update CrOS logout button for MD.

ui/views/controls/button/md_text_button.cc

Index: ui/views/controls/button/md_text_button.cc
diff --git a/ui/views/controls/button/md_text_button.cc b/ui/views/controls/button/md_text_button.cc
index ebb275ea5cc56a4559bf107646258818b68a89e7..3d3e5310cb472a1131a56ffc70276d1b6289be7a 100644
--- a/ui/views/controls/button/md_text_button.cc
+++ b/ui/views/controls/button/md_text_button.cc
@@ -136,6 +136,11 @@ void MdTextButton::PaintMdFocusRing(gfx::Canvas* canvas,
   canvas->DrawRoundRect(rect, kFocusBorderCornerRadius, paint);
 }
 
+void MdTextButton::AdjustFontSize(int size_delta) {
+  SetFontList(GetFontList().DeriveWithSizeDelta(size_delta));
+  UpdatePaddingForFont();
+}
+
 void MdTextButton::SetCallToAction(bool cta) {
   if (is_cta_ == cta)
     return;
@@ -221,12 +226,16 @@ MdTextButton::MdTextButton(ButtonListener* listener)
   SetMinSize(gfx::Size(kMinWidth, 0));
   SetFocusPainter(nullptr);
   label()->SetAutoColorReadabilityEnabled(false);
-  SetFontList(GetMdFontList());
-
   AddChildView(focus_ring_);
   focus_ring_->SetVisible(false);
   set_request_focus_on_press(false);
+  SetFontList(GetMdFontList());
+  UpdatePaddingForFont();
+}
+
+MdTextButton::~MdTextButton() {}
 
+void MdTextButton::UpdatePaddingForFont() {
   // Top and bottom padding depend on the font. Example: if font cap height is
   // 9dp, use 8dp bottom padding and 7dp top padding to total 24dp.
   const gfx::FontList& font = label()->font_list();
@@ -247,8 +256,6 @@ MdTextButton::MdTextButton(ButtonListener* listener)
       bottom_padding - inbuilt_bottom_padding, kHorizontalPadding));
 }
 
-MdTextButton::~MdTextButton() {}
-
 void MdTextButton::UpdateColors() {
   ui::NativeTheme::ColorId fg_color_id =
       is_cta_ ? ui::NativeTheme::kColorId_TextOnCallToActionColor