MacViews: Implement Full Keyboard Access.

ui/views/controls/button/md_text_button.cc

 // Copyright 2015 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.
 
 #include "ui/views/controls/button/md_text_button.h"
 
 #include "base/i18n/case_conversion.h"
 #include "ui/base/material_design/material_design_controller.h"
 #include "ui/gfx/color_utils.h"
 #include "ui/native_theme/native_theme.h"
@@ skipping 58 matching lines @@
   LabelButton::SetText(base::i18n::ToUpper(text));
 }
 
 MdTextButton::MdTextButton(ButtonListener* listener)
     : LabelButton(listener, base::string16()),
       ink_drop_delegate_(this, this),
       cta_(NO_CALL_TO_ACTION) {
   set_ink_drop_delegate(&ink_drop_delegate_);
   set_has_ink_drop_action_on_click(true);
   SetHorizontalAlignment(gfx::ALIGN_CENTER);
-  SetFocusable(true);
+  Button::ConfigureDefaultFocus(this);
   SetMinSize(gfx::Size(kMinWidth, 0));
   SetFocusPainter(nullptr);
   UseMdFocusRing();
   label()->SetAutoColorReadabilityEnabled(false);
 }
 
 MdTextButton::~MdTextButton() {}
 
 void MdTextButton::UpdateColorsFromNativeTheme() {
   ui::NativeTheme::ColorId fg_color_id = ui::NativeTheme::kColorId_NumColors;
@@ skipping 15 matching lines @@
       cta_ == STRONG_CALL_TO_ACTION
           ? Background::CreateBackgroundPainter(
                 true, Painter::CreateSolidRoundRectPainter(
                           theme->GetSystemColor(
                               ui::NativeTheme::kColorId_CallToActionColor),
                           kInkDropSmallCornerRadius))
           : nullptr);
 }
 
 }  // namespace views