Add GetLowerCaseElementAttributeOrDefault() helper function.

CXFA_TextParser::GetEmbeddedObj() does the same thing twice in a row.
Change-Id: Ia46a0a697ff667b2884cea82258399889dbb5dc6
Reviewed-on: https://pdfium-review.googlesource.com/40775
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Ryan Harrison <rharrison@chromium.org>

xfa/fxfa/cxfa_textparser.cpp

diff --git a/xfa/fxfa/cxfa_textparser.cpp b/xfa/fxfa/cxfa_textparser.cpp
index b2b4747..3084783 100644
--- a/xfa/fxfa/cxfa_textparser.cpp
+++ b/xfa/fxfa/cxfa_textparser.cpp
@@ -41,6 +41,18 @@
   Location,
 };
 
+WideString GetLowerCaseElementAttributeOrDefault(
+    const CFX_XMLElement* pElement,
+    const WideString& wsName,
+    const WideString& wsDefaultValue) {
+  WideString ws = pElement->GetAttribute(wsName);
+  if (ws.IsEmpty())
+    ws = wsDefaultValue;
+  else
+    ws.MakeLower();
+  return ws;
+}
+
 }  // namespace
 
 CXFA_TextParser::CXFA_TextParser()
@@ -512,19 +524,13 @@
   if (wsAttr[0] == L'#')
     wsAttr.Delete(0);
 
-  WideString ws = pElement->GetAttribute(L"xfa:embedType");
-  if (ws.IsEmpty())
-    ws = L"som";
-  else
-    ws.MakeLower();
+  WideString ws =
+      GetLowerCaseElementAttributeOrDefault(pElement, L"xfa:embedType", L"som");
   if (ws != L"uri")
     return {};
 
-  ws = pElement->GetAttribute(L"xfa:embedMode");
-  if (ws.IsEmpty())
-    ws = L"formatted";
-  else
-    ws.MakeLower();
+  ws = GetLowerCaseElementAttributeOrDefault(pElement, L"xfa:embedMode",
+                                             L"formatted");
   if (ws != L"raw" && ws != L"formatted")
     return {};