Makes tile-creation lazy

cc/layers/picture_image_layer_impl_unittest.cc

Index: cc/layers/picture_image_layer_impl_unittest.cc
diff --git a/cc/layers/picture_image_layer_impl_unittest.cc b/cc/layers/picture_image_layer_impl_unittest.cc
index 5e8b1d82fd601634acd3bf9740df2c2a14420b84..abedc8d33f2e320fa9bf58fdfd206832f85e27ac 100644
--- a/cc/layers/picture_image_layer_impl_unittest.cc
+++ b/cc/layers/picture_image_layer_impl_unittest.cc
@@ -35,8 +35,8 @@ class PictureImageLayerImplTest : public testing::Test {
     TestablePictureImageLayerImpl* layer =
         new TestablePictureImageLayerImpl(host_impl_.pending_tree(), id);
     layer->SetBounds(gfx::Size(100, 200));
-    layer->tilings_.reset(new PictureLayerTilingSet(&tiling_client_));
-    layer->tilings_->SetLayerBounds(layer->bounds());
+    layer->tilings_.reset(new PictureLayerTilingSet(&tiling_client_,
+                                                    layer->bounds()));
     layer->pile_ = tiling_client_.pile();
     return make_scoped_ptr(layer);
   }