Reduce views::Border creation verbosity by promoting factory functions

ash/common/system/chromeos/virtual_keyboard/virtual_keyboard_tray.cc

 // Copyright 2014 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 "ash/common/system/chromeos/virtual_keyboard/virtual_keyboard_tray.h"
 
 #include <algorithm>
 
 #include "ash/common/keyboard/keyboard_ui.h"
 #include "ash/common/material_design/material_design_controller.h"
@@ skipping 85 matching lines @@
     const gfx::Rect& new_bounds) {
   SetDrawBackgroundAsActive(!new_bounds.IsEmpty());
 }
 
 void VirtualKeyboardTray::OnKeyboardClosed() {}
 
 void VirtualKeyboardTray::SetIconBorderForShelfAlignment() {
   // Every time shelf alignment is updated, StatusAreaWidgetDelegate resets the
   // border to a non-null border. So, we need to remove it.
   if (!ash::MaterialDesignController::IsShelfMaterial())
-    tray_container()->SetBorder(views::Border::NullBorder());
+    tray_container()->SetBorder(views::NullBorder());
   const gfx::ImageSkia& image = icon_->GetImage();
   const int size = GetTrayConstant(VIRTUAL_KEYBOARD_BUTTON_SIZE);
   const int vertical_padding = (size - image.height()) / 2;
   int horizontal_padding = (size - image.width()) / 2;
   if (!ash::MaterialDesignController::IsShelfMaterial() &&
       IsHorizontalAlignment(shelf_alignment())) {
     // Square up the padding if horizontally aligned. Avoid extra padding when
     // vertically aligned as the button would violate the width constraint on
     // the shelf.
     horizontal_padding += std::max(0, vertical_padding - horizontal_padding);
   }
-  icon_->SetBorder(views::Border::CreateEmptyBorder(
+  icon_->SetBorder(views::CreateEmptyBorder(
       gfx::Insets(vertical_padding, horizontal_padding)));
 }
 
 void VirtualKeyboardTray::ObserveKeyboardController() {
   keyboard::KeyboardController* keyboard_controller =
       keyboard::KeyboardController::GetInstance();
   if (keyboard_controller)
     keyboard_controller->AddObserver(this);
 }
 
 void VirtualKeyboardTray::UnobserveKeyboardController() {
   keyboard::KeyboardController* keyboard_controller =
       keyboard::KeyboardController::GetInstance();
   if (keyboard_controller)
     keyboard_controller->RemoveObserver(this);
 }
 
 }  // namespace ash