Nuke WebPassOwnPtr<T> and replace it with std::unique_ptr<T>.

content/renderer/media/rtc_certificate.h

 // Copyright (c) 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 CONTENT_RENDERER_MEDIA_RTC_CERTIFICATE_H_
 #define CONTENT_RENDERER_MEDIA_RTC_CERTIFICATE_H_
 
 #include <stdint.h>
 
 #include "base/macros.h"
 #include "third_party/WebKit/public/platform/WebRTCCertificate.h"
 #include "third_party/WebKit/public/platform/WebRTCKeyParams.h"
 #include "third_party/webrtc/base/rtccertificate.h"
 #include "third_party/webrtc/base/scoped_ref_ptr.h"
 
 namespace content {
 
 // Chromium's WebRTCCertificate implementation; wraps a rtc::scoped_refptr to an
 // rtc::RTCCertificate. This abstraction layer is necessary because blink does
 // not have direct access to WebRTC.
 class RTCCertificate : public blink::WebRTCCertificate {
  public:
   RTCCertificate(const blink::WebRTCKeyParams& key_params,
                  const rtc::scoped_refptr<rtc::RTCCertificate>& certificate);
   ~RTCCertificate() override;
 
   // blink::WebRTCCertificate implementation.
-  blink::WebPassOwnPtr<blink::WebRTCCertificate> shallowCopy() const override;
+  std::unique_ptr<blink::WebRTCCertificate> shallowCopy() const override;
   const blink::WebRTCKeyParams& keyParams() const override;
   uint64_t expires() const override;
 
   const rtc::scoped_refptr<rtc::RTCCertificate>& rtcCertificate() const;
 
  private:
   blink::WebRTCKeyParams key_params_;
   rtc::scoped_refptr<rtc::RTCCertificate> certificate_;
 
   DISALLOW_COPY_AND_ASSIGN(RTCCertificate);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_RTC_CERTIFICATE_H_