Convert //ios from scoped_ptr to std::unique_ptr.

ios/chrome/browser/net/image_fetcher_unittest.mm

 // 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.
 
 #import "ios/chrome/browser/net/image_fetcher.h"
 
 #import <UIKit/UIKit.h>
 
 #include "base/ios/ios_util.h"
 #include "base/mac/scoped_block.h"
@@ skipping 85 matching lines @@
     net::TestURLFetcher* fetcher = factory_.GetFetcherByID(0);
     DCHECK(fetcher);
     DCHECK(fetcher->delegate());
     return fetcher;
   }
 
   base::MessageLoop loop_;
   base::mac::ScopedBlock<image_fetcher::ImageFetchedCallback> callback_;
   net::TestURLFetcherFactory factory_;
   scoped_refptr<base::SequencedWorkerPool> pool_;
-  scoped_ptr<image_fetcher::ImageFetcher> image_fetcher_;
+  std::unique_ptr<image_fetcher::ImageFetcher> image_fetcher_;
   UIImage* result_;
   bool called_;
 };
 
 TEST_F(ImageFetcherTest, TestError) {
   net::TestURLFetcher* fetcher = SetupFetcher();
   fetcher->set_response_code(404);
   fetcher->delegate()->OnURLFetchComplete(fetcher);
   EXPECT_EQ(static_cast<UIImage*>(nil), result_);
   EXPECT_TRUE(called_);
@@ skipping 67 matching lines @@
   EXPECT_EQ(static_cast<UIImage*>(nil), result_);
   EXPECT_FALSE(called_);
 }
 
 TEST_F(ImageFetcherTest, TestCallbacksNotCalledDuringDeletion) {
   image_fetcher_->StartDownload(GURL(kTestUrl), callback_);
   image_fetcher_.reset();
   EXPECT_FALSE(called_);
 }