Make iterator a stack variable in CFDE_TextEditEngine::RebuildPieces()

One less make_unique<CFDE_...>

Change-Id: I355ba4a37d4e82be9989287fcd6c6d18f642a724
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/73870
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

xfa/fde/cfde_texteditengine.cpp

diff --git a/xfa/fde/cfde_texteditengine.cpp b/xfa/fde/cfde_texteditengine.cpp
index 2e36c60..28e8f66 100644
--- a/xfa/fde/cfde_texteditengine.cpp
+++ b/xfa/fde/cfde_texteditengine.cpp
@@ -1085,13 +1085,13 @@
   size_t current_piece_start = 0;
   float current_line_start = 0;
 
-  auto iter = std::make_unique<CFDE_TextEditEngine::Iterator>(this);
-  while (!iter->IsEOF(false)) {
-    iter->Next(false);
+  CFDE_TextEditEngine::Iterator iter(this);
+  while (!iter.IsEOF(false)) {
+    iter.Next(false);
 
     CFX_BreakType break_status = text_break_.AppendChar(
-        password_mode_ ? password_alias_ : iter->GetChar());
-    if (iter->IsEOF(false) && CFX_BreakTypeNoneOrPiece(break_status))
+        password_mode_ ? password_alias_ : iter.GetChar());
+    if (iter.IsEOF(false) && CFX_BreakTypeNoneOrPiece(break_status))
       break_status = text_break_.EndBreak(CFX_BreakType::kParagraph);
 
     if (CFX_BreakTypeNoneOrPiece(break_status))