Fix Mac sandbox meta data access

content/common/sandbox_mac.mm

Index: content/common/sandbox_mac.mm
diff --git a/content/common/sandbox_mac.mm b/content/common/sandbox_mac.mm
index c7c126594aec3fb2abae774f3359e9a3a1b83c81..4067e326461465fbe2a197bf7637d983072b9c49 100644
--- a/content/common/sandbox_mac.mm
+++ b/content/common/sandbox_mac.mm
@@ -114,12 +114,14 @@ NSString* Sandbox::AllowMetadataForPath(const base::FilePath& allowed_path) {
   // Collect a list of all parent directories.
   base::FilePath last_path = allowed_path;
   std::vector<base::FilePath> subpaths;
-  for (base::FilePath path = allowed_path;
-       path.value() != last_path.value();
-       path = path.DirName()) {
+
+  base::FilePath path = allowed_path;
+  do {
     subpaths.push_back(path);
+
     last_path = path;
-  }
+    path = path.DirName();
+  } while (path.value() != last_path.value());
 
   // Iterate through all parents and allow stat() on them explicitly.
   NSString* sandbox_command = @"(allow file-read-metadata ";