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

ios/chrome/browser/net/retryable_url_fetcher.mm

 // Copyright 2014 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/retryable_url_fetcher.h"
 
+#include <memory>
+
 #include "base/logging.h"
-#include "base/memory/scoped_ptr.h"
 #include "base/strings/sys_string_conversions.h"
 #include "net/http/http_status_code.h"
 #include "net/url_request/url_fetcher.h"
 #include "net/url_request/url_fetcher_delegate.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "url/gurl.h"
 
 @interface RetryableURLFetcher ()
 - (void)urlFetchDidComplete:(const net::URLFetcher*)fetcher;
 @end
 
 class URLRequestDelegate : public net::URLFetcherDelegate {
  public:
   explicit URLRequestDelegate(RetryableURLFetcher* owner) : owner_(owner) {}
   void OnURLFetchComplete(const net::URLFetcher* source) override {
     [owner_ urlFetchDidComplete:source];
   }
 
  private:
   RetryableURLFetcher* owner_;  // Weak.
 };
 
 @implementation RetryableURLFetcher {
   scoped_refptr<net::URLRequestContextGetter> requestContextGetter_;
-  scoped_ptr<URLRequestDelegate> fetcherDelegate_;
-  scoped_ptr<net::URLFetcher> fetcher_;
-  scoped_ptr<net::BackoffEntry> backoffEntry_;
+  std::unique_ptr<URLRequestDelegate> fetcherDelegate_;
+  std::unique_ptr<net::URLFetcher> fetcher_;
+  std::unique_ptr<net::BackoffEntry> backoffEntry_;
   int retryCount_;
   id<RetryableURLFetcherDelegate> delegate_;  // Weak.
 }
 
 - (instancetype)
     initWithRequestContextGetter:(net::URLRequestContextGetter*)context
                         delegate:(id<RetryableURLFetcherDelegate>)delegate
                    backoffPolicy:(const net::BackoffEntry::Policy*)policy {
   self = [super init];
   if (self) {
@@ skipping 37 matching lines @@
   NSString* response = nil;
   if (success) {
     std::string responseString;
     if (fetcher->GetResponseAsString(&responseString))
       response = base::SysUTF8ToNSString(responseString);
   }
   [delegate_ processSuccessResponse:response];
 }
 
 @end