Fix nits in CPDF_ClipPath.

- Use: = default.
- Add operator= since the class already has a copy ctor.
- Remove unneeded forward declaration / #include.
- Replace a #define with a real constant.

Change-Id: Ifdaa4ae320edc5e7e80e5ce3583122bb956656f9
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/60851
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/core/fpdfapi/page/cpdf_clippath.cpp b/core/fpdfapi/page/cpdf_clippath.cpp
index 5db9208..53b602d 100644
--- a/core/fpdfapi/page/cpdf_clippath.cpp
+++ b/core/fpdfapi/page/cpdf_clippath.cpp
@@ -8,16 +8,15 @@
 
 #include <utility>
 
-#include "core/fpdfapi/page/cpdf_path.h"
 #include "core/fpdfapi/page/cpdf_textobject.h"
 
-#define FPDF_CLIPPATH_MAX_TEXTS 1024
+CPDF_ClipPath::CPDF_ClipPath() = default;
 
-CPDF_ClipPath::CPDF_ClipPath() {}
+CPDF_ClipPath::CPDF_ClipPath(const CPDF_ClipPath& that) = default;
 
-CPDF_ClipPath::CPDF_ClipPath(const CPDF_ClipPath& that) : m_Ref(that.m_Ref) {}
+CPDF_ClipPath& CPDF_ClipPath::operator=(const CPDF_ClipPath& that) = default;
 
-CPDF_ClipPath::~CPDF_ClipPath() {}
+CPDF_ClipPath::~CPDF_ClipPath() = default;
 
 size_t CPDF_ClipPath::GetPathCount() const {
   return m_Ref.GetObject()->m_PathAndTypeList.size();
@@ -93,8 +92,9 @@
 
 void CPDF_ClipPath::AppendTexts(
     std::vector<std::unique_ptr<CPDF_TextObject>>* pTexts) {
+  constexpr size_t kMaxTextObjects = 1024;
   PathData* pData = m_Ref.GetPrivateCopy();
-  if (pData->m_TextList.size() + pTexts->size() <= FPDF_CLIPPATH_MAX_TEXTS) {
+  if (pData->m_TextList.size() + pTexts->size() <= kMaxTextObjects) {
     for (size_t i = 0; i < pTexts->size(); i++)
       pData->m_TextList.push_back(std::move((*pTexts)[i]));
     pData->m_TextList.push_back(nullptr);
diff --git a/core/fpdfapi/page/cpdf_clippath.h b/core/fpdfapi/page/cpdf_clippath.h
index 0e807c1..aff2839 100644
--- a/core/fpdfapi/page/cpdf_clippath.h
+++ b/core/fpdfapi/page/cpdf_clippath.h
@@ -15,13 +15,13 @@
 #include "core/fxcrt/fx_coordinates.h"
 #include "core/fxcrt/shared_copy_on_write.h"
 
-class CPDF_Path;
 class CPDF_TextObject;
 
 class CPDF_ClipPath {
  public:
   CPDF_ClipPath();
   CPDF_ClipPath(const CPDF_ClipPath& that);
+  CPDF_ClipPath& operator=(const CPDF_ClipPath& that);
   ~CPDF_ClipPath();
 
   void Emplace() { m_Ref.Emplace(); }