Refactor WebRTC certificate generation to use WebPassOwnPtr.

content/renderer/media/rtc_certificate.cc

Index: content/renderer/media/rtc_certificate.cc
diff --git a/content/renderer/media/rtc_certificate.cc b/content/renderer/media/rtc_certificate.cc
index 9a1ce11d5134f5a67923a98e5f581a00fd76c735..19ec478dacb54f71cd1d8703e2a8dd7efa780d7c 100644
--- a/content/renderer/media/rtc_certificate.cc
+++ b/content/renderer/media/rtc_certificate.cc
@@ -19,8 +19,9 @@ RTCCertificate::RTCCertificate(
 RTCCertificate::~RTCCertificate() {
 }
 
-RTCCertificate* RTCCertificate::shallowCopy() const {
-  return new RTCCertificate(key_params_, certificate_);
+blink::WebPassOwnPtr<blink::WebRTCCertificate> RTCCertificate::shallowCopy()
+    const {
+  return blink::adoptWebPtr(new RTCCertificate(key_params_, certificate_));
 }
 
 const blink::WebRTCKeyParams& RTCCertificate::keyParams() const {