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diff --git a/xpcom/base/RLBoxUtils.h b/xpcom/base/RLBoxUtils.h
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+++ b/xpcom/base/RLBoxUtils.h
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+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef SECURITY_RLBOX_UTILS_H_
+#define SECURITY_RLBOX_UTILS_H_
+
+#include "mozilla/rlbox/rlbox_types.hpp"
+
+namespace mozilla {
+
+/* The RLBoxTransferBufferToSandbox class is used to copy (or directly expose in
+ * the noop-sandbox case) buffers into the sandbox that are automatically freed
+ * when the RLBoxTransferBufferToSandbox is out of scope.  NOTE: The sandbox
+ * lifetime must outlive all of its RLBoxTransferBufferToSandbox.
+ */
+template <typename T, typename S>
+class MOZ_STACK_CLASS RLBoxTransferBufferToSandbox {
+ public:
+  RLBoxTransferBufferToSandbox() = delete;
+  RLBoxTransferBufferToSandbox(rlbox::rlbox_sandbox<S>* aSandbox, const T* aBuf,
+                               const size_t aLen)
+      : mSandbox(aSandbox), mCopied(false), mBuf(nullptr) {
+    if (aBuf) {
+      mBuf = rlbox::copy_memory_or_grant_access(*mSandbox, aBuf, aLen, false,
+                                                mCopied);
+    }
+  };
+  ~RLBoxTransferBufferToSandbox() {
+    if (mCopied) {
+      mSandbox->free_in_sandbox(mBuf);
+    }
+  };
+  rlbox::tainted<const T*, S> operator*() const { return mBuf; };
+
+ private:
+  rlbox::rlbox_sandbox<S>* mSandbox;
+  bool mCopied;
+  rlbox::tainted<const T*, S> mBuf;
+};
+
+/* The RLBoxAllocateInSandbox class is used to allocate data int sandbox that is
+ * automatically freed when the RLBoxAllocateInSandbox is out of scope.  NOTE:
+ * The sandbox lifetime must outlive all of its RLBoxAllocateInSandbox'ations.
+ */
+template <typename T, typename S>
+class MOZ_STACK_CLASS RLBoxAllocateInSandbox {
+ public:
+  RLBoxAllocateInSandbox() = delete;
+  explicit RLBoxAllocateInSandbox(rlbox::rlbox_sandbox<S>* aSandbox)
+      : mSandbox(aSandbox) {
+    mPtr = mSandbox->template malloc_in_sandbox<T>();
+  };
+  ~RLBoxAllocateInSandbox() {
+    if (mPtr) {
+      mSandbox->free_in_sandbox(mPtr);
+    }
+  };
+  rlbox::tainted<T*, S> get() const { return mPtr; };
+
+ private:
+  rlbox::rlbox_sandbox<S>* mSandbox;
+  rlbox::tainted<T*, S> mPtr;
+};
+
+}  // namespace mozilla
+
+#endif