Update include/base headers for C++11/14 (see issue #3140)

See the issue for update guidelines.

libcef_dll/base/cef_callback_helpers.cc

@@ -0,0 +1,43 @@
+// Copyright 2013 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 "include/base/cef_callback_helpers.h"
+
+namespace base {
+
+ScopedClosureRunner::ScopedClosureRunner() = default;
+
+ScopedClosureRunner::ScopedClosureRunner(OnceClosure closure)
+    : closure_(std::move(closure)) {}
+
+ScopedClosureRunner::ScopedClosureRunner(ScopedClosureRunner&& other)
+    : closure_(other.Release()) {}
+
+ScopedClosureRunner& ScopedClosureRunner::operator=(
+    ScopedClosureRunner&& other) {
+  if (this != &other) {
+    RunAndReset();
+    ReplaceClosure(other.Release());
+  }
+  return *this;
+}
+
+ScopedClosureRunner::~ScopedClosureRunner() {
+  RunAndReset();
+}
+
+void ScopedClosureRunner::RunAndReset() {
+  if (closure_)
+    std::move(closure_).Run();
+}
+
+void ScopedClosureRunner::ReplaceClosure(OnceClosure closure) {
+  closure_ = std::move(closure);
+}
+
+OnceClosure ScopedClosureRunner::Release() {
+  return std::move(closure_);
+}
+
+}  // namespace base