1 files changed, 50 insertions, 0 deletions
diff --git a/third_party/chromium/base/template_util.h b/third_party/chromium/base/template_util.h
index 0c3cac2..158daf1 100644
--- a/third_party/chromium/base/template_util.h
+++ b/third_party/chromium/base/template_util.h
@@ -5,16 +5,66 @@
 #ifndef BASE_TEMPLATE_UTIL_H_
 #define BASE_TEMPLATE_UTIL_H_
 
+#include <iosfwd>
 #include <type_traits>
+#include <utility>
 
 #include "build/build_config.h"
 
+// This hacks around libstdc++ 4.6 missing stuff in type_traits, while we need
+// to support it.
+#define CR_GLIBCXX_4_7_0 20120322
+#define CR_GLIBCXX_4_5_4 20120702
+#define CR_GLIBCXX_4_6_4 20121127
+#if defined(__GLIBCXX__) &&                                               \
+    (__GLIBCXX__ < CR_GLIBCXX_4_7_0 || __GLIBCXX__ == CR_GLIBCXX_4_5_4 || \
+     __GLIBCXX__ == CR_GLIBCXX_4_6_4)
+#define CR_USE_FALLBACKS_FOR_OLD_GLIBCXX
+#endif
+
 namespace base {
 
 template <class T> struct is_non_const_reference : std::false_type {};
 template <class T> struct is_non_const_reference<T&> : std::true_type {};
 template <class T> struct is_non_const_reference<const T&> : std::false_type {};
 
+namespace internal {
+// Uses expression SFINAE to detect whether using operator<< would work.
+template <typename T, typename = void>
+struct SupportsOstreamOperator : std::false_type {};
+template <typename T>
+struct SupportsOstreamOperator<T,
+                               decltype(void(std::declval<std::ostream&>()
+                                             << std::declval<T>()))>
+    : std::true_type {};
+
+}  // namespace internal
+
+// underlying_type produces the integer type backing an enum type.
+// TODO(crbug.com/554293): Remove this when all platforms have this in the std
+// namespace.
+#if defined(CR_USE_FALLBACKS_FOR_OLD_GLIBCXX)
+template <typename T>
+struct underlying_type {
+  using type = __underlying_type(T);
+};
+#else
+template <typename T>
+using underlying_type = std::underlying_type<T>;
+#endif
+
+// TODO(crbug.com/554293): Remove this when all platforms have this in the std
+// namespace.
+#if defined(CR_USE_FALLBACKS_FOR_OLD_GLIBCXX)
+template <class T>
+using is_trivially_destructible = std::has_trivial_destructor<T>;
+#else
+template <class T>
+using is_trivially_destructible = std::is_trivially_destructible<T>;
+#endif
+
 }  // namespace base
 
+#undef CR_USE_FALLBACKS_FOR_OLD_GLIBCXX
+
 #endif  // BASE_TEMPLATE_UTIL_H_