Rewrite scoped_ptr<T>(NULL) to use the default ctor in cc/.

cc/layers/tiled_layer_unittest.cc

 // Copyright 2011 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 "cc/layers/tiled_layer.h"
 
 #include <limits>
 #include <vector>
 
 #include "cc/debug/overdraw_metrics.h"
@@ skipping 38 matching lines @@
       : proxy_(NULL),
         output_surface_(CreateFakeOutputSurface()),
         queue_(make_scoped_ptr(new ResourceUpdateQueue)),
         fake_layer_impl_tree_host_client_(FakeLayerTreeHostClient::DIRECT_3D),
         occlusion_(NULL) {
     settings_.max_partial_texture_updates = std::numeric_limits<size_t>::max();
     settings_.layer_transforms_should_scale_layer_contents = true;
   }
 
   virtual void SetUp() {
-    layer_tree_host_ = LayerTreeHost::Create(&fake_layer_impl_tree_host_client_,
-                                             settings_,
-                                             scoped_ptr<Thread>(NULL));
+    layer_tree_host_ = LayerTreeHost::Create(
+        &fake_layer_impl_tree_host_client_, settings_, scoped_ptr<Thread>());
     proxy_ = layer_tree_host_->proxy();
     resource_manager_ = PrioritizedResourceManager::Create(proxy_);
     layer_tree_host_->InitializeOutputSurfaceIfNeeded();
     layer_tree_host_->SetRootLayer(Layer::Create());
 
     DebugScopedSetImplThreadAndMainThreadBlocked
     impl_thread_and_main_thread_blocked(proxy_);
     resource_provider_ = ResourceProvider::Create(output_surface_.get(), 0);
     host_impl_ = make_scoped_ptr(new FakeLayerTreeHostImpl(proxy_));
   }
@@ skipping 1774 matching lines @@
   // Invalidate the entire layer in layer space. When painting, the rect given
   // to webkit should match the layer's bounds.
   layer->SetNeedsDisplayRect(layer_rect);
   layer->Update(queue_.get(), 0, NULL);
 
   EXPECT_RECT_EQ(layer_rect, layer->tracking_layer_painter()->PaintedRect());
 }
 
 }  // namespace
 }  // namespace cc