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

cc/resources/prioritized_resource_unittest.cc

 // Copyright 2012 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/resources/prioritized_resource.h"
 
 #include "cc/resources/prioritized_resource_manager.h"
 #include "cc/resources/resource.h"
 #include "cc/test/fake_output_surface.h"
 #include "cc/test/fake_proxy.h"
 #include "cc/test/tiled_layer_test_common.h"
 #include "cc/trees/single_thread_proxy.h"  // For DebugScopedSetImplThread
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace cc {
 
 class PrioritizedResourceTest : public testing::Test {
  public:
   PrioritizedResourceTest()
-      : proxy_(scoped_ptr<Thread>(NULL)),
+      : proxy_(scoped_ptr<Thread>()),
         texture_size_(256, 256),
         texture_format_(GL_RGBA),
         output_surface_(CreateFakeOutputSurface()) {
     DebugScopedSetImplThread impl_thread(&proxy_);
     resource_provider_ = cc::ResourceProvider::Create(output_surface_.get(), 0);
   }
 
   virtual ~PrioritizedResourceTest() {
     DebugScopedSetImplThread impl_thread(&proxy_);
     resource_provider_.reset();
@@ skipping 762 matching lines @@
               resource_manager->MemoryVisibleAndNearbyBytes());
   }
 
   DebugScopedSetImplThreadAndMainThreadBlocked
   impl_thread_and_main_thread_blocked(&proxy_);
   resource_manager->ClearAllMemory(ResourceProvider());
 }
 
 }  // namespace
 }  // namespace cc