[MD] Use same focus ring on BarControlButton as MdTextButton.

chrome/browser/ui/views/bar_control_button.cc

Index: chrome/browser/ui/views/bar_control_button.cc
diff --git a/chrome/browser/ui/views/bar_control_button.cc b/chrome/browser/ui/views/bar_control_button.cc
index eecd5186b365e18fd90fc46186759b24c171021b..cef871b2736449854f48a521da4baf2cc109979a 100644
--- a/chrome/browser/ui/views/bar_control_button.cc
+++ b/chrome/browser/ui/views/bar_control_button.cc
@@ -9,6 +9,7 @@
 #include "ui/gfx/vector_icons_public.h"
 #include "ui/views/animation/button_ink_drop_delegate.h"
 #include "ui/views/border.h"
+#include "ui/views/painter.h"
 
 namespace {
 
@@ -25,6 +26,8 @@ BarControlButton::BarControlButton(views::ButtonListener* listener)
   set_has_ink_drop_action_on_click(true);
   SetImageAlignment(views::ImageButton::ALIGN_CENTER,
                     views::ImageButton::ALIGN_MIDDLE);
+  SetFocusPainter(nullptr);
+  UseMdFocusRing();
 }
 
 BarControlButton::~BarControlButton() {}
@@ -50,6 +53,7 @@ void BarControlButton::OnThemeChanged() {
   image = gfx::CreateVectorIcon(id_, 16, SkColorSetA(icon_color, 0xff / 2));
   SetImage(views::CustomButton::STATE_DISABLED, &image);
   set_ink_drop_base_color(icon_color);
+  SizeToPreferredSize();

[sky, 2016/03/22 15:31:40]

What view has BarControlButton in it? I get nervous with random
SizeToPreferredSize as that is generally better down in the parent doing the
layout.

[Evan Stade, 2016/03/22 17:35:44]

infobarview, find bar, download shelf. The alternative is to reimplement
GetPreferredSize so it returns the right thing even before OnThemeChanged, but
that seemed like slightly duplicate logic to me and I couldn't think of a way
sizing this here would cause harm. The button is not likely to do the right
thing/look right if you don't size it to its preferred size so in some sense
it's an error if a parent doesn't do this.

[sky, 2016/03/22 18:02:27]

Doesn't find bar and the like need to relayout in this case? What triggers that?

[Evan Stade, 2016/03/22 18:16:11]

This code path gets hit as soon as BarControlButton is added to the child
hierarchy (AddChildView -> OnNativeThemeChanged -> OnThemeChanged). The parent
will necessarily call Layout() after this.

Granted, this won't work if subsequent theme changes were to change the size of
the button, which they currently don't. Another way to write this would be:

if (parent() && size() != GetPreferredSize())
  parent()->Layout();

but then the parent has to call SizeToPreferredSize (in the sense that it's
probably an error to size it to anything else).

 }
 
 void BarControlButton::OnNativeThemeChanged(const ui::NativeTheme* theme) {