Use nine image painter to draw tray background

ui/base/nine_image_painter_factory.h

 // 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.
 
 #ifndef UI_BASE_NINE_IMAGE_PAINTER_FACTORY_H_
 #define UI_BASE_NINE_IMAGE_PAINTER_FACTORY_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "ui/base/ui_base_export.h"
 
 // A macro to define arrays of IDR constants used with CreateImageGridPainter.
 #define IMAGE_GRID(x) { x ## _TOP_LEFT,    x ## _TOP,    x ## _TOP_RIGHT, \
                         x ## _LEFT,        x ## _CENTER, x ## _RIGHT, \
                         x ## _BOTTOM_LEFT, x ## _BOTTOM, x ## _BOTTOM_RIGHT, }
 
 // Defines a empty image for used in macro for creating image grid for a ring of
 // eight images.
 #define EMPTY_IMAGE 0
 
 // A macro to define arrays of IDR constants used with CreateImageGridPainter
 // where only a ring of eight images is provided and center image is empty.
 #define IMAGE_GRID_NO_CENTER(x) { x ## _TOP_LEFT, x ## _TOP, x ## _TOP_RIGHT, \
       x ## _LEFT, EMPTY_IMAGE, x ## _RIGHT, \
       x ## _BOTTOM_LEFT, x ## _BOTTOM, x ## _BOTTOM_RIGHT, }
 
+// A macro to define arrays of IDR constants used with CreateImageGridPainter
+// where it can only be streched horizontally.
+#define IMAGE_GRID_HORIZONTAL(x) { x ## _LEFT, x ## _CENTER, x ## _RIGHT, \
+      EMPTY_IMAGE, EMPTY_IMAGE, EMPTY_IMAGE, \
+      EMPTY_IMAGE, EMPTY_IMAGE, EMPTY_IMAGE}
+
+// A macro to define arrays of IDR constants used with CreateImageGridPainter
+// where it can only be streched vertically.
+#define IMAGE_GRID_VERTICAL(x) { x ## _TOP, EMPTY_IMAGE, EMPTY_IMAGE, \
+        x ## _CENTER, EMPTY_IMAGE, EMPTY_IMAGE, \
+        x ## _BOTTOM, EMPTY_IMAGE, EMPTY_IMAGE}
 
 namespace gfx {
 class NineImagePainter;
 }
 
 namespace ui {
 
 // Creates a NineImagePainter from an array of image ids. It's expected the
 // array came from the IMAGE_GRID macro.
 UI_BASE_EXPORT scoped_ptr<gfx::NineImagePainter> CreateNineImagePainter(
     const int image_ids[]);
 
 }  // namespace ui
 
 #endif  // UI_BASE_NINE_IMAGE_PAINTER_FACTORY_H_