Move string16 and char16 in to base::

base/strings/string16.h

Index: base/strings/string16.h
diff --git a/base/strings/string16.h b/base/strings/string16.h
index f7e64dbfca3ab9e57a8993f75833a4fecf925ccf..5e6d431dcfd45b2df7848470e66c53516a5dfdaa 100644
--- a/base/strings/string16.h
+++ b/base/strings/string16.h
@@ -10,10 +10,10 @@
 
 #include <string>
 
-typedef uint16_t char16;
-
 namespace base {
 
+typedef uint16_t char16;
+
 int c16memcmp(const char16* s1, const char16* s2, size_t n);
 size_t c16len(const char16* s);
 const char16* c16memchr(const char16* s, char16 c, size_t n);
@@ -88,16 +88,13 @@ struct string16_char_traits {
   }
 };
 
-}  // namespace base
-
-extern template class std::basic_string<char16, base::string16_char_traits>;
-
 typedef std::basic_string<char16, base::string16_char_traits> string16;
 
-namespace base {
-
 extern std::ostream& operator<<(std::ostream& out, const string16& str);
 
 }  // namespace base
 
+extern template class std::basic_string<base::char16,
+                                        base::string16_char_traits>;
+
 #endif  // MINI_CHROMIUM_BASE_STRINGS_STRING16_H_