Add the button style for combobox

ui/views/controls/focusable_border.cc

 // Copyright (c) 2012 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/focusable_border.h"
 
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/insets.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/native_theme/native_theme.h"
@@ skipping 46 matching lines @@
 }
 
 gfx::Insets FocusableBorder::GetInsets() const {
   return insets_;
 }
 
 gfx::Size FocusableBorder::GetMinimumSize() const {
   return gfx::Size();
 }
 
+void FocusableBorder::ResetInsets() {
+  SetInsets(kTopInsetSize, kLeftInsetSize, kBottomInsetSize, kRightInsetSize);
+}
+
 void FocusableBorder::SetInsets(int top, int left, int bottom, int right) {
   insets_.Set(top, left, bottom, right);
 }
 
 }  // namespace views