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());

[sky, 2016/07/27 19:57:07]

As anyone can call SetFontList, shouldn't you make it so that when the font
changes you automatically update padding?

[Evan Stade, 2016/07/27 20:09:47]

are you suggesting making SetFontList virtual? I'm kinda hoping no one will want
to (or be allowed to) use that function on MdTextButtons although there's
nothing enforcing that today. If we make the API more restrictive, like
AdjustFontSize(), it encourages people to do the right thing. Here's an example
of existing usage that I think should be discouraged:

just_once_button_->SetFontList(gfx::FontList("Roboto-medium, 13px"));

When just_once_button_ is an MdTextButton this should instead be
just_once_button_->AdjustFontSize(1);

Most usages of SetFontList appear to use FontStyle, e.g.

  no_show_checkbox_->SetFontList(
      ui::ResourceBundle::GetSharedInstance().GetFontList(
      ui::ResourceBundle::MediumFont));

and I agree with Trent's comment here[1] that it should be phased out.

[1]
https://cs.chromium.org/chromium/src/ui/base/resource/resource_bundle.h?rcl=1...

+  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