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

content/renderer/media/rtc_certificate.cc

 // 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.
 
 #include "content/renderer/media/rtc_certificate.h"
 
+#include "base/memory/ptr_util.h"
 #include "content/renderer/media/peer_connection_identity_store.h"
 #include "url/gurl.h"
 
 namespace content {
 
 RTCCertificate::RTCCertificate(
     const blink::WebRTCKeyParams& key_params,
     const rtc::scoped_refptr<rtc::RTCCertificate>& certificate)
     : key_params_(key_params), certificate_(certificate) {
   DCHECK(certificate_);
 }
 
 RTCCertificate::~RTCCertificate() {
 }
 
-blink::WebPassOwnPtr<blink::WebRTCCertificate> RTCCertificate::shallowCopy()
-    const {
-  return blink::adoptWebPtr(new RTCCertificate(key_params_, certificate_));
+std::unique_ptr<blink::WebRTCCertificate> RTCCertificate::shallowCopy() const {
+  return base::WrapUnique(new RTCCertificate(key_params_, certificate_));
 }
 
 const blink::WebRTCKeyParams& RTCCertificate::keyParams() const {
   return key_params_;
 }
 
 uint64_t RTCCertificate::expires() const {
   return certificate_->Expires();
 }
 
 const rtc::scoped_refptr<rtc::RTCCertificate>&
 RTCCertificate::rtcCertificate() const {
   return certificate_;
 }
 
 }  // namespace content