Convert //ash from scoped_ptr to std::unique_ptr

ash/shelf/scoped_observer_with_duplicated_sources_unittest.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 "ash/shelf/scoped_observer_with_duplicated_sources.h"
 
-#include "base/memory/scoped_ptr.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 class TestObserver {
  public:
   TestObserver() {}
   ~TestObserver() {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TestObserver);
 };
@@ skipping 55 matching lines @@
   observers.Remove(&source2);
   EXPECT_EQ(0, source2.GetObserverCount());
   EXPECT_FALSE(observers.IsObserving(&source2));
 
   // Remove |source1| again.
   observers.Remove(&source1);
   // In this time, |observer| is removed from |source1|.
   EXPECT_EQ(0, source1.GetObserverCount());
   EXPECT_FALSE(observers.IsObserving(&source1));
 }