Revert of Unconditionally include <string> and <iostream> in json_reader.cpp

third_party/jsoncpp/overrides/src/lib_json/json_reader.cpp

Index: third_party/jsoncpp/overrides/src/lib_json/json_reader.cpp
diff --git a/third_party/jsoncpp/overrides/src/lib_json/json_reader.cpp b/third_party/jsoncpp/overrides/src/lib_json/json_reader.cpp
index 43c20cd024f1c2b1caadc6bea0e00ee9c3b83f7d..1bc7429993b7543dd94e6a169c439e27409c98e6 100644
--- a/third_party/jsoncpp/overrides/src/lib_json/json_reader.cpp
+++ b/third_party/jsoncpp/overrides/src/lib_json/json_reader.cpp
@@ -14,14 +14,16 @@
 #include <cassert>
 #include <cstring>
 #include <stdexcept>
+#ifdef __pnacl__
 // This file uses the following headers (at least in Reader::parse), but
 // the upstream version doesn't include them because iostream pulls in
-// static initializers.  This breaks builds that use libc++ (including PNaCl),
-// because libc++ declares getline in <string> (as per the C++ standard)
+// static initializers.  This breaks the PNaCl build because it uses
+// libc++ which declares getline in <string> (as per the C++ standard)
 // but defines it in <iostream>. The code therefore fails linking, which
 // these includes fix.
 #include <string>
 #include <iostream>
+#endif
 
 #if _MSC_VER >= 1400 // VC++ 8.0
 #pragma warning( disable : 4996 )   // disable warning about strdup being deprecated.