Some additions to support symlinks better on platforms that support them.

base/platform_file.h

Index: base/platform_file.h
diff --git a/base/platform_file.h b/base/platform_file.h
index b350f8c9b36f6b7782c892bebbf0f7d2f820039b..1ca98686f856c5b58dab3747e46605dd86de2bff 100644
--- a/base/platform_file.h
+++ b/base/platform_file.h
@@ -77,6 +77,9 @@ struct PlatformFileInfo {
   // True if the file corresponds to a directory.
   bool is_directory;
 
+  // True if the file corresponds to a symbolic link.
+  bool is_symbolic_link;
+
   // The last modified time of a file.
   base::Time last_modified;