Make more variables const-ref.chromium/3373

Found by ClangTidy.

BUG=pdfium:1040

Change-Id: I6d7cb26ae2d12f5650f73596d0b991234b076f57
Reviewed-on: https://pdfium-review.googlesource.com/28712
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

3 files changed, 13 insertions, 11 deletions

diff --git a/core/fxcrt/xml/cfx_xmlinstruction.cpp b/core/fxcrt/xml/cfx_xmlinstruction.cpp
index dabd538b4b..35b68e4d7d 100644
--- a/core/fxcrt/xml/cfx_xmlinstruction.cpp
+++ b/core/fxcrt/xml/cfx_xmlinstruction.cpp
@@ -62,7 +62,7 @@ void CFX_XMLInstruction::Save(
         AttributeToString(it.first, it.second).AsStringView());
   }
 
-  for (auto target : m_TargetData) {
+  for (const WideString& target : m_TargetData) {
     WideString ws = L" \"";
     ws += target;
     ws += L"\"";
diff --git a/core/fxcrt/xml/cfx_xmlnode.cpp b/core/fxcrt/xml/cfx_xmlnode.cpp
index 1851a4d81e..5e787ed2b9 100644
--- a/core/fxcrt/xml/cfx_xmlnode.cpp
+++ b/core/fxcrt/xml/cfx_xmlnode.cpp
@@ -110,16 +110,18 @@ std::unique_ptr<CFX_XMLNode> CFX_XMLNode::Clone() {
 
 void CFX_XMLNode::Save(const RetainPtr<CFX_SeekableStreamProxy>& pXMLStream) {}
 
-WideString CFX_XMLNode::EncodeEntities(WideString value) {
-  value.Replace(L"&", L"&amp;");
-  value.Replace(L"<", L"&lt;");
-  value.Replace(L">", L"&gt;");
-  value.Replace(L"\'", L"&apos;");
-  value.Replace(L"\"", L"&quot;");
-  return value;
+WideString CFX_XMLNode::EncodeEntities(const WideString& value) {
+  WideString ret = value;
+  ret.Replace(L"&", L"&amp;");
+  ret.Replace(L"<", L"&lt;");
+  ret.Replace(L">", L"&gt;");
+  ret.Replace(L"\'", L"&apos;");
+  ret.Replace(L"\"", L"&quot;");
+  return ret;
 }
 
-WideString CFX_XMLNode::AttributeToString(WideString name, WideString value) {
+WideString CFX_XMLNode::AttributeToString(const WideString& name,
+                                          const WideString& value) {
   WideString ret = L" ";
   ret += name;
   ret += L"=\"";
diff --git a/core/fxcrt/xml/cfx_xmlnode.h b/core/fxcrt/xml/cfx_xmlnode.h
index cf2158af5b..76625e3ca2 100644
--- a/core/fxcrt/xml/cfx_xmlnode.h
+++ b/core/fxcrt/xml/cfx_xmlnode.h
@@ -45,8 +45,8 @@ class CFX_XMLNode {
   void DeleteChildren();
 
  protected:
-  WideString AttributeToString(WideString name, WideString value);
-  WideString EncodeEntities(WideString value);
+  WideString AttributeToString(const WideString& name, const WideString& value);
+  WideString EncodeEntities(const WideString& value);
 
  private:
   CFX_XMLNode* parent_ = nullptr;