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

third_party/WebKit/Source/wtf/PtrUtil.h

Index: third_party/WebKit/Source/wtf/PtrUtil.h
diff --git a/third_party/WebKit/Source/wtf/PtrUtil.h b/third_party/WebKit/Source/wtf/PtrUtil.h
new file mode 100644
index 0000000000000000000000000000000000000000..1c19fd8d98ece3c9751f417b2b49b8bf5575a682
--- /dev/null
+++ b/third_party/WebKit/Source/wtf/PtrUtil.h
@@ -0,0 +1,27 @@
+// Copyright 2016 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 PtrUtil_h
+#define PtrUtil_h
+
+#include "wtf/TypeTraits.h"
+
+#include <memory>
+
+namespace WTF {
+
+template<typename T>
+std::unique_ptr<T> wrapUnique(T* ptr)
+{
+    static_assert(
+        !WTF::IsGarbageCollectedType<T>::value,
+        "Garbage collected types should not be stored in std::unique_ptr!");
+    return std::unique_ptr<T>(ptr);
+}
+
+} // namespace WTF
+
+using WTF::wrapUnique;
+
+#endif // PtrUtil_h