Move safe_strerror to posix directory and the base namespace

base/logging.cc

Index: base/logging.cc
diff --git a/base/logging.cc b/base/logging.cc
index 2f1d837a00d3e52bcbd783961fa79539b5d53b53..71528ad3f4ece402cdc70a65cf947a5d2d9d2ca8 100644
--- a/base/logging.cc
+++ b/base/logging.cc
@@ -59,7 +59,7 @@ typedef pthread_mutex_t* MutexHandle;
 #include "base/threading/platform_thread.h"
 #include "base/vlog.h"
 #if defined(OS_POSIX)
-#include "base/safe_strerror_posix.h"
+#include "base/posix/safe_strerror.h"
 #endif
 
 #if defined(OS_ANDROID)
@@ -719,7 +719,7 @@ BASE_EXPORT std::string SystemErrorCodeToString(SystemErrorCode error_code) {
 }
 #elif defined(OS_POSIX)
 BASE_EXPORT std::string SystemErrorCodeToString(SystemErrorCode error_code) {
-  return safe_strerror(error_code);
+  return base::safe_strerror(error_code);
 }
 #else
 #error Not implemented