Refactor Pickle Read methods to use higher performance PickleIterator.

chrome/browser/sessions/base_session_service.cc

Index: chrome/browser/sessions/base_session_service.cc
diff --git a/chrome/browser/sessions/base_session_service.cc b/chrome/browser/sessions/base_session_service.cc
index a529d31c4026a4d8c830d3e699cbcd2ae52f8064..9a00ce92010d086965e6cbbb563a43be6565d374 100644
--- a/chrome/browser/sessions/base_session_service.cc
+++ b/chrome/browser/sessions/base_session_service.cc
@@ -254,7 +254,7 @@ bool BaseSessionService::RestoreUpdateTabNavigationCommand(
   scoped_ptr<Pickle> pickle(command.PayloadAsPickle());
   if (!pickle.get())
     return false;
-  void* iterator = NULL;
+  PickleReader iterator(*pickle);
   std::string url_spec;
   if (!pickle->ReadInt(&iterator, tab_id) ||
       !pickle->ReadInt(&iterator, &(navigation->index_)) ||
@@ -306,7 +306,7 @@ bool BaseSessionService::RestoreSetTabExtensionAppIDCommand(
   if (!pickle.get())
     return false;
 
-  void* iterator = NULL;
+  PickleReader iterator(*pickle);
   return pickle->ReadInt(&iterator, tab_id) &&
       pickle->ReadString(&iterator, extension_app_id);
 }