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

ios/web/interstitials/native_web_interstitial_impl.h

 // Copyright 2015 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.
 
 #ifndef IOS_WEB_INTERSTITIALS_NATIVE_WEB_INTERSTITIAL_IMPL_H_
 #define IOS_WEB_INTERSTITIALS_NATIVE_WEB_INTERSTITIAL_IMPL_H_
 
 #include "ios/web/interstitials/web_interstitial_impl.h"
 
 #include "base/ios/weak_nsobject.h"
 #include "base/mac/scoped_nsobject.h"
 
 namespace web {
 
 class NativeWebInterstitialDelegate;
 
 // A concrete subclass of WebInterstitialImpl that is used to display
 // interstitials created via native views.
 class NativeWebInterstitialImpl : public WebInterstitialImpl {
  public:
-  NativeWebInterstitialImpl(WebStateImpl* web_state,
-                            bool new_navigation,
-                            const GURL& url,
-                            scoped_ptr<NativeWebInterstitialDelegate> delegate);
+  NativeWebInterstitialImpl(
+      WebStateImpl* web_state,
+      bool new_navigation,
+      const GURL& url,
+      std::unique_ptr<NativeWebInterstitialDelegate> delegate);
   ~NativeWebInterstitialImpl() override;
 
   // WebInterstitialImpl implementation:
   CRWContentView* GetContentView() const override;
 
  protected:
   // WebInterstitialImpl implementation:
   void PrepareForDisplay() override;
   WebInterstitialDelegate* GetDelegate() const override;
   void EvaluateJavaScript(NSString* script,
                           JavaScriptCompletion completionHandler) override;
 
  private:
   // The native interstitial delegate.
-  scoped_ptr<NativeWebInterstitialDelegate> delegate_;
+  std::unique_ptr<NativeWebInterstitialDelegate> delegate_;
   // The transient content view containing interstitial content.
   base::scoped_nsobject<CRWContentView> content_view_;
 };
 
 }  // namespace web
 
 #endif  // IOS_WEB_INTERSTITIALS_NATIVE_WEB_INTERSTITIAL_IMPL_H_