Refactor Pickle Read methods to use higher performance PickleIterator.

base/file_path.h

Index: base/file_path.h
diff --git a/base/file_path.h b/base/file_path.h
index bde3cec30c21e53002408469446a3761b1717654..4d763eb394c1cca1eb11225a753a185f05e0c947 100644
--- a/base/file_path.h
+++ b/base/file_path.h
@@ -122,6 +122,7 @@
 #endif  // OS_WIN
 
 class Pickle;
+class PickleIterator;
 
 // An abstraction to isolate users from the differences between native
 // pathnames on different platforms.
@@ -339,7 +340,7 @@ class BASE_EXPORT FilePath {
   static FilePath FromUTF8Unsafe(const std::string& utf8);
 
   void WriteToPickle(Pickle* pickle);
-  bool ReadFromPickle(Pickle* pickle, void** iter);
+  bool ReadFromPickle(PickleIterator* iter);
 
   // Normalize all path separators to backslash on Windows
   // (if FILE_PATH_USES_WIN_SEPARATORS is true), or do nothing on POSIX systems.