Refactor Pickle Read methods to use higher performance PickleIterator.

net/http/http_vary_data.h

Index: net/http/http_vary_data.h
diff --git a/net/http/http_vary_data.h b/net/http/http_vary_data.h
index baa4d881a0643beaf9cddd1fc557d0e3d1e5f128..1acc16c6fe78d9c4cd027d5be46bd9d9e25f5bf6 100644
--- a/net/http/http_vary_data.h
+++ b/net/http/http_vary_data.h
@@ -10,6 +10,7 @@
 #include "net/base/net_export.h"
 
 class Pickle;
+class PickleReader;
 
 namespace net {
 
@@ -52,7 +53,7 @@ class NET_EXPORT_PRIVATE HttpVaryData {
   // is_valid() will return true.  Otherwise, false is returned to indicate
   // that this object is marked as invalid.
   //
-  bool InitFromPickle(const Pickle& pickle, void** pickle_iter);
+  bool InitFromPickle(const Pickle& pickle, PickleReader* pickle_iter);
 
   // Call this method to persist the vary data. Illegal to call this on an
   // invalid object.