Make all NSPR symbols "private extern"

base/third_party/nspr/prtypes.h

Index: base/third_party/nspr/prtypes.h
===================================================================
--- base/third_party/nspr/prtypes.h	(revision 29127)
+++ base/third_party/nspr/prtypes.h	(working copy)
@@ -88,8 +88,32 @@
 **
 **
 ***********************************************************************/
-#if defined(WIN32)
+#if 1
 
+/*
+** Chrome-local change: the portions of NSPR used for Chrome are
+** implementation details of Chrome's base module.  NSPR symbols do not need
+** to be exported beyond the module in which they are used.  For all
+** platforms, avoid decorating functions with specific visibility and access
+** keywords.
+*/
+
+#define PR_EXPORT(__type) extern __type
+#define PR_EXPORT_DATA(__type) extern __type
+#define PR_IMPORT(__type) extern __type
+#define PR_IMPORT_DATA(__type) extern __type
+
+#define PR_EXTERN(__type) extern __type
+#define PR_IMPLEMENT(__type) __type
+#define PR_EXTERN_DATA(__type) extern __type
+#define PR_IMPLEMENT_DATA(__type) __type
+
+#define PR_CALLBACK
+#define PR_CALLBACK_DECL
+#define PR_STATIC_CALLBACK(__x) static __x
+
+#elif defined(WIN32)
+
 #define PR_EXPORT(__type) extern __declspec(dllexport) __type
 #define PR_EXPORT_DATA(__type) extern __declspec(dllexport) __type
 #define PR_IMPORT(__type) extern __type