Change ui::wm::Shadow to use cc::NinePatchLayer.

ui/compositor/layer.cc

Index: ui/compositor/layer.cc
diff --git a/ui/compositor/layer.cc b/ui/compositor/layer.cc
index c1767422163a523d837632b6183a6100b5dab2cc..450c615fefad4e263d59a58c8f8c3ad10364a19a 100644
--- a/ui/compositor/layer.cc
+++ b/ui/compositor/layer.cc
@@ -14,6 +14,7 @@
 #include "cc/base/scoped_ptr_algorithm.h"
 #include "cc/layers/content_layer.h"
 #include "cc/layers/delegated_renderer_layer.h"
+#include "cc/layers/nine_patch_layer.h"
 #include "cc/layers/picture_layer.h"
 #include "cc/layers/solid_color_layer.h"
 #include "cc/layers/texture_layer.h"
@@ -583,6 +584,28 @@ void Layer::SetShowPaintedContent() {
   RecomputeDrawsContentAndUVRect();
 }
 
+void Layer::SetShowNinePatch() {
+  if (nine_patch_layer_.get())
+    return;
+
+  scoped_refptr<cc::NinePatchLayer> new_layer = cc::NinePatchLayer::Create();
+  SetFillsBoundsOpaquely(false);
+
+  SwitchToLayer(new_layer);
+  nine_patch_layer_ = new_layer;
+}
+
+void Layer::UpdateNinePatchBitmap(const SkBitmap& bitmap,
+                                  const gfx::Rect& aperture,
+                                  const gfx::Rect& border) {
+  if (!nine_patch_layer_.get())
+    return;
+
+  nine_patch_layer_->SetBitmap(bitmap);
+  nine_patch_layer_->SetAperture(aperture);
+  nine_patch_layer_->SetBorder(border);
+}
+
 void Layer::SetColor(SkColor color) { GetAnimator()->SetColor(color); }
 
 bool Layer::SchedulePaint(const gfx::Rect& invalid_rect) {