cc: nine patch: add occlusion support

mash/wm/shadow.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 "mash/wm/shadow.h"
 
 #include "mash/wm/property_util.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/compositor/layer.h"
@@ skipping 181 matching lines @@
 
   // Update the shadow aperture and border for style. Note that border is in
   // layer space and it cannot exceed the bounds of the layer.
   int aperture = GetShadowApertureForStyle(style_);
   int aperture_x = std::min(aperture, layer_bounds.width() / 2);
   int aperture_y = std::min(aperture, layer_bounds.height() / 2);
   shadow_layer_->UpdateNinePatchLayerAperture(
       gfx::Rect(aperture_x, aperture_y,
                 image_size_.width() - aperture_x * 2,
                 image_size_.height() - aperture_y * 2));
-  shadow_layer_->UpdateNinePatchLayerBorder(
-      gfx::Rect(aperture_x, aperture_y, aperture_x * 2, aperture_y * 2));
+  shadow_layer_->UpdateNinePatchOcclusion(
+      content_bounds_ + gfx::Vector2d(interior_inset_, interior_inset_));
 }
 
 void Shadow::OnWindowDestroyed(mus::Window* window) {
   DCHECK_EQ(window_, window);
   window_ = nullptr;
 }
 
 }  // namespace wm
 }  // namespace mash