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

third_party/WebKit/Source/modules/background_sync/SyncCallbacks.cpp

Index: third_party/WebKit/Source/modules/background_sync/SyncCallbacks.cpp
diff --git a/third_party/WebKit/Source/modules/background_sync/SyncCallbacks.cpp b/third_party/WebKit/Source/modules/background_sync/SyncCallbacks.cpp
index 9e2af89a3640bab5b8cd852574dec70695d51237..9b6e3e7cb993da72fe7a40c85c109755dcd9c5ed 100644
--- a/third_party/WebKit/Source/modules/background_sync/SyncCallbacks.cpp
+++ b/third_party/WebKit/Source/modules/background_sync/SyncCallbacks.cpp
@@ -24,13 +24,13 @@ SyncRegistrationCallbacks::~SyncRegistrationCallbacks()
 {
 }
 
-void SyncRegistrationCallbacks::onSuccess(WebPassOwnPtr<WebSyncRegistration> webSyncRegistration)
+void SyncRegistrationCallbacks::onSuccess(std::unique_ptr<WebSyncRegistration> webSyncRegistration)
 {
     if (!m_resolver->getExecutionContext() || m_resolver->getExecutionContext()->activeDOMObjectsAreStopped()) {
         return;
     }
 
-    OwnPtr<WebSyncRegistration> registration = webSyncRegistration.release();
+    OwnPtr<WebSyncRegistration> registration = adoptPtr(webSyncRegistration.release());

[dcheng, 2016/04/07 00:26:12]

FWIW, I think we'd be saving ourself trouble down the road if you could just
write std::move(webSyncRegistration) here.

     if (!registration) {
         m_resolver->resolve(v8::Null(m_resolver->getScriptState()->isolate()));
         return;