Fix clang pc plugin warnings

Bug: chromium:1056170
Change-Id: Ifd93017bb4070573ed086ff22bde28029db7bb87
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/82370
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/xfa/fxfa/cxfa_ffdocview.cpp b/xfa/fxfa/cxfa_ffdocview.cpp
index 4e007b4..e04e69c 100644
--- a/xfa/fxfa/cxfa_ffdocview.cpp
+++ b/xfa/fxfa/cxfa_ffdocview.cpp
@@ -532,7 +532,7 @@
   if (!pGlobalData)
     return;
 
-  for (auto pResult : pGlobalData->m_Globals) {
+  for (auto& pResult : pGlobalData->m_Globals) {
     if (!pResult->HasRemovedChildren() && pResult->IsWidgetReady())
       AddCalculateNode(pResult);
   }
diff --git a/xfa/fxfa/cxfa_ffpageview.cpp b/xfa/fxfa/cxfa_ffpageview.cpp
index 527acfe..7a49aaf 100644
--- a/xfa/fxfa/cxfa_ffpageview.cpp
+++ b/xfa/fxfa/cxfa_ffpageview.cpp
@@ -161,13 +161,8 @@
   CXFA_TabParam& operator=(const CXFA_TabParam&) = delete;
   CXFA_TabParam& operator=(CXFA_TabParam&&) noexcept = default;
 
-  void Trace(cppgc::Visitor* visitor) const {
-    visitor->Trace(m_pItem);
-    ContainerTrace(visitor, m_Children);
-  }
-
   CXFA_FFWidget* GetWidget() const { return m_pItem->GetFFWidget(); }
-  const std::vector<cppgc::Member<CXFA_ContentLayoutItem>>& GetChildren()
+  const std::vector<cppgc::Persistent<CXFA_ContentLayoutItem>>& GetChildren()
       const {
     return m_Children;
   }
@@ -179,8 +174,8 @@
   }
 
  private:
-  cppgc::Member<CXFA_ContentLayoutItem> m_pItem;
-  std::vector<cppgc::Member<CXFA_ContentLayoutItem>> m_Children;
+  cppgc::Persistent<CXFA_ContentLayoutItem> m_pItem;
+  std::vector<cppgc::Persistent<CXFA_ContentLayoutItem>> m_Children;
 };
 
 void OrderContainer(CXFA_LayoutItemIterator* sIterator,