Add InRangeCast<> and its test

util/numeric/in_range_cast.h

+// Copyright 2014 The Crashpad Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef CRASHPAD_UTIL_NUMERIC_IN_RANGE_CAST_H_
+#define CRASHPAD_UTIL_NUMERIC_IN_RANGE_CAST_H_
+
+#include "base/logging.h"
+#include "base/numerics/safe_conversions.h"
+
+namespace crashpad {
+
+//! \brief Casts to a different type if it can be done without data loss,
+//!     logging a warning message and returing a default value otherwise.
+//!
+//! \param[in] source The value to convert and return.
+//! \param[in] default_value The default value to return, in the event that \a
+//!     source cannot be represented in the destination type.
+//!
+//! \return \a source if it can be represented in the destination type,
+//!     otherwise \a default_value.
+template <typename Destination, typename Source>
+Destination InRangeCast(Source source, Destination default_value) {
+  if (base::IsValueInRangeForNumericType<Destination>(source)) {
+    return source;
+  }
+
+  LOG(WARNING) << "value " << source << " out of range";
+  return default_value;
+}
+
+}  // namespace crashpad
+
+#endif  // CRASHPAD_UTIL_NUMERIC_IN_RANGE_CAST_H_