Refactor ViewsDelegate and MD-ify the icon-to-text spacing for checkbox and radiobutton

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 b5e6c1b0e1e98ef5c9151ffb11d85053fe5f3ecb..d134878bbd7eb1c97064bab3168ea44c470ee76b 100644
--- a/ui/views/controls/button/md_text_button.cc
+++ b/ui/views/controls/button/md_text_button.cc
@@ -193,8 +193,8 @@ MdTextButton::MdTextButton(ButtonListener* listener)
   set_has_ink_drop_action_on_click(true);
   SetHorizontalAlignment(gfx::ALIGN_CENTER);
   SetFocusForPlatform();
-  const int minimum_width =
-      ViewsDelegate::GetInstance()->GetButtonMinimumWidth();
+  const int minimum_width = ViewsDelegate::GetInstance()->GetSpacingMetric(
+      SpacingMetric::DIALOG_BUTTON_MINIMUM_WIDTH);
   SetMinSize(gfx::Size(minimum_width, 0));
   SetFocusPainter(nullptr);
   label()->SetAutoColorReadabilityEnabled(false);
@@ -240,8 +240,8 @@ void MdTextButton::UpdatePadding() {
 
   // TODO(estade): can we get rid of the platform style border hoopla if
   // we apply the MD treatment to all buttons, even GTK buttons?
-  const int horizontal_padding =
-      ViewsDelegate::GetInstance()->GetButtonHorizontalPadding();
+  const int horizontal_padding = ViewsDelegate::GetInstance()->GetSpacingMetric(
+      SpacingMetric::BUTTON_HORIZONTAL_PADDING);
   SetBorder(CreateEmptyBorder(top_padding, horizontal_padding, bottom_padding,
                               horizontal_padding));
 }