Make CopyDirectory() not copy the read only bit on Windows.

base/file_util.h

Index: base/file_util.h
diff --git a/base/file_util.h b/base/file_util.h
index f8418318a6a7ecd92255e6d708624b7f1ae6bcf7..7dca89288e04899dda6ab0c094c59481496a7a14 100644
--- a/base/file_util.h
+++ b/base/file_util.h
@@ -97,6 +97,8 @@ BASE_EXPORT bool ReplaceFile(const FilePath& from_path,
 
 // Copies a single file. Use CopyDirectory to copy directories.
 // This function fails if either path contains traversal components ('..').
+//
+// This function doesn't keep the metadata of from_path except on OSX.
 BASE_EXPORT bool CopyFile(const FilePath& from_path, const FilePath& to_path);
 
 // Copies the given path, and optionally all subdirectories and their contents
@@ -105,6 +107,8 @@ BASE_EXPORT bool CopyFile(const FilePath& from_path, const FilePath& to_path);
 // If there are files existing under to_path, always overwrite. Returns true
 // if successful, false otherwise. Wildcards on the names are not supported.
 //
+// This function doesn't keep the metadata of from_path except on OSX.
+//
 // If you only need to copy a file use CopyFile, it's faster.
 BASE_EXPORT bool CopyDirectory(const FilePath& from_path,
                                const FilePath& to_path,