Update base.cc to check for COMPILER_MSVC or _WIN32.

Author: jasonriesa

src/base.cc

@@ -16,21 +16,21 @@ limitations under the License.
 #include "base.h"
 
 #include <string>
-#ifdef _WIN32
+#if defined(COMPILER_MSVC) || defined(_WIN32)
 #include <sstream>
-#endif  // _WIN32
+#endif  // defined(COMPILER_MSVC) || defined(_WIN32)
 
 namespace chrome_lang_id {
 
 // TODO(abakalov): Pick the most efficient approach.
-#ifdef _WIN32
+#if defined(COMPILER_MSVC) || defined(_WIN32)
 std::string Int64ToString(int64 input) {
   std::stringstream stream;
   stream << input;
   return stream.str();
 }
 #else
 std::string Int64ToString(int64 input) { return std::to_string(input); }
-#endif  // _WIN32
+#endif  // defined(COMPILER_MSVC) || defined(_WIN32)
 
 }  // namespace chrome_lang_id