Revert of Allow $TMPDIR to set temporary directory on OS X.

remoting/host/mac/me2me_preference_pane.mm

Index: remoting/host/mac/me2me_preference_pane.mm
diff --git a/remoting/host/mac/me2me_preference_pane.mm b/remoting/host/mac/me2me_preference_pane.mm
index d64b67e14b4124218eb6ddedc4bac7171f123992..cc17b670e0b73d70ee3800dbb198c69f8044a5de 100644
--- a/remoting/host/mac/me2me_preference_pane.mm
+++ b/remoting/host/mac/me2me_preference_pane.mm
@@ -17,7 +17,6 @@
 #include <fstream>
 #include <memory>
 
-#include "base/files/file_util.h"
 #include "base/mac/authorization_util.h"
 #include "base/mac/launchd.h"
 #include "base/mac/mac_logging.h"
@@ -34,16 +33,12 @@
 namespace {
 
 bool GetTemporaryConfigFilePath(std::string* path) {
-  base::FilePath ret;
-
-  if (!base::GetTempPath(&ret)) {
+  NSString* filename = NSTemporaryDirectory();
+  if (filename == nil)
     return false;
-  }
-
-  ret = ret.Append(remoting::kHostConfigFileName);
-
-  // This should be safe on OS X because utf8 is always supported.
-  *path = ret.AsUTF8Unsafe();
+
+  *path = [[NSString stringWithFormat:@"%@/%s",
+            filename, remoting::kHostConfigFileName] UTF8String];
   return true;
 }