layers: Consolidate the ownership of layers in views::View and aura::Window.

ui/views/view_unittest.cc

Index: ui/views/view_unittest.cc
diff --git a/ui/views/view_unittest.cc b/ui/views/view_unittest.cc
index 3ebd39e47d879e5865ef48a6b3bf51b0e80323d6..b6ea244460662d28ef9c4ca38429dc934c59a70d 100644
--- a/ui/views/view_unittest.cc
+++ b/ui/views/view_unittest.cc
@@ -3160,6 +3160,21 @@ TEST_F(ViewLayerTest, ReorderUnderWidget) {
   EXPECT_EQ(c2->layer(), parent_layer->children()[0]);
 }
 
+// Verifies that the layer of a view can be acquired properly.
+TEST_F(ViewLayerTest, AcquireLayer) {
+  View* content = new View;
+  widget()->SetContentsView(content);
+  View* c1 = new View;
+  c1->SetPaintToLayer(true);
+  EXPECT_TRUE(c1->layer());
+
+  scoped_ptr<ui::Layer> layer(c1->AcquireLayer());
+  EXPECT_EQ(layer.get(), c1->layer());
+
+  layer.reset(c1->RecreateLayer());
+  EXPECT_NE(c1->layer(), layer.get());
+}
+
 #endif  // USE_AURA
 
 }  // namespace views