Unify some code

core/fpdfapi/parser/cpdf_linearized.cpp

Index: core/fpdfapi/parser/cpdf_linearized.cpp
diff --git a/core/fpdfapi/parser/cpdf_linearized.cpp b/core/fpdfapi/parser/cpdf_linearized.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..50c71399b4175453dd859dc637de338440c3d8eb
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_linearized.cpp
@@ -0,0 +1,52 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_linearized.h"
+
+#include <algorithm>
+
+#include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "third_party/base/ptr_util.h"
+
+// static
+std::unique_ptr<CPDF_Linearized> CPDF_Linearized::CreateForObject(
+    std::unique_ptr<CPDF_Object, ReleaseDeleter<CPDF_Object>> pObj) {
+  UniqueDictionary pDict = ToDictionary(std::move(pObj));
+  if (!pDict || !pDict->GetObjectFor("Linearized"))
+    return nullptr;
+  auto result = pdfium::WrapUnique(new CPDF_Linearized(pDict.get()));
+  if (result->IsValid())
+    return result;
+  return nullptr;
+}
+
+CPDF_Linearized::CPDF_Linearized(const CPDF_Dictionary* pDict) {
+  m_szFileSize = std::max(pDict->GetIntegerFor("L"), 0);
+  m_dwFirstPageNo = std::max(pDict->GetIntegerFor("P"), 0);
+  m_szLastXRefOffset = std::max(pDict->GetIntegerFor("T"), 0);
+  m_PageCount = std::max(pDict->GetIntegerFor("N"), 0);
+  m_szFirstPageEndOffset = std::max(pDict->GetIntegerFor("E"), 0);
+  m_FirstPageObjNum = std::max(pDict->GetIntegerFor("O"), 0);
+  const CPDF_Array* pHintStreamRange = pDict->GetArrayFor("H");
+  const size_t nHintStreamSize =
+      pHintStreamRange ? pHintStreamRange->GetCount() : 0;
+  if (nHintStreamSize == 2 || nHintStreamSize == 4) {
+    m_szHintStart = std::max(pHintStreamRange->GetIntegerAt(0), 0);
+    m_szHintLength = std::max(pHintStreamRange->GetIntegerAt(1), 0);
+  }
+}
+
+CPDF_Linearized::~CPDF_Linearized() {}
+
+bool CPDF_Linearized::IsValid() const {
+  return GetFileSize() > 0 && GetFirstPageEndOffset() > 0 &&
+         GetPageCount() > 0 && (GetPageCount() == 1 || GetLastXRefOffset() > 0);
+}
+
+bool CPDF_Linearized::HasHintTable() const {
+  return GetPageCount() > 1 && GetHintStart() > 0 && GetHintLength() > 0;
+}