cc: Change scoped_ptr<T>() to nullptr.

cc/resources/picture_layer_tiling_perftest.cc

 // Copyright 2013 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/debug/lap_timer.h"
 #include "cc/resources/picture_layer_tiling.h"
 #include "cc/resources/resource_provider.h"
 #include "cc/resources/scoped_resource.h"
 #include "cc/test/fake_output_surface.h"
 #include "cc/test/fake_output_surface_client.h"
@@ skipping 242 matching lines @@
       timer_.NextLap();
     } while (!timer_.HasTimeLimitExpired());
 
     // Remove all resources from tiles to make sure the tile version destructor
     // doesn't complain.
     for (std::vector<Tile*>::iterator tile_it = all_tiles.begin();
          tile_it != all_tiles.end();
          ++tile_it) {
       Tile* tile = *tile_it;
       ManagedTileState::DrawInfo& draw_info = tile->draw_info();
-      draw_info.SetResourceForTesting(scoped_ptr<ScopedResource>());
+      draw_info.SetResourceForTesting(nullptr);
     }
 
     perf_test::PrintResult(
         "tiling_eviction_tile_iterator_construct_and_iterate",
         "",
         test_name,
         timer_.LapsPerSecond(),
         "runs/s",
         true);
   }
@@ skipping 78 matching lines @@
       "32_500x500", 32, gfx::Rect(0, 0, 500, 500));
   RunEvictionIteratorConstructAndIterateTest(
       "64_100x100", 64, gfx::Rect(0, 0, 100, 100));
   RunEvictionIteratorConstructAndIterateTest(
       "64_500x500", 64, gfx::Rect(0, 0, 500, 500));
 }
 
 }  // namespace
 
 }  // namespace cc