Traverse PDF page tree only once in CPDF_Document Try 3

core/fpdfapi/parser/cpdf_document.h

Index: core/fpdfapi/parser/cpdf_document.h
diff --git a/core/fpdfapi/parser/cpdf_document.h b/core/fpdfapi/parser/cpdf_document.h
index e1135260ee0543aea0c0d01449ca88ce4e7bbfe7..a9f58f358dc796bc4facf2f9951e8c4269516c83 100644
--- a/core/fpdfapi/parser/cpdf_document.h
+++ b/core/fpdfapi/parser/cpdf_document.h
@@ -105,10 +105,7 @@ class CPDF_Document : public CPDF_IndirectObjectHolder {
  protected:
   // Retrieve page count information by getting count value from the tree nodes
   int RetrievePageCount() const;
-  CPDF_Dictionary* FindPDFPage(CPDF_Dictionary* pPages,
-                               int iPage,
-                               int nPagesToGo,
-                               int level);
+  CPDF_Dictionary* TraversePDFPages(int iPage, int& nPagesToGo, int level);

[Tom Sepez, 2016/11/03 22:31:00]

nit: the style guide would say int* nPagesToGo. 

[npm, 2016/11/04 19:33:33]

Done.

   int FindPageIndex(CPDF_Dictionary* pNode,
                     uint32_t& skip_count,
                     uint32_t objnum,
@@ -134,6 +131,11 @@ class CPDF_Document : public CPDF_IndirectObjectHolder {
   std::unique_ptr<CPDF_Parser> m_pParser;
   CPDF_Dictionary* m_pRootDict;
   CPDF_Dictionary* m_pInfoDict;
+  // Vector of nodes to know current position in the page tree. Int is the index

[Lei Zhang, 2016/11/04 01:38:52]

Maybe mention the index into this vector is the level, and what both values in
the pair represent.

[npm, 2016/11/04 19:33:33]

Done.

+  // of the child being processed.

[Tom Sepez, 2016/11/03 22:31:00]

nit:  // of the child being processed within the dictionary's /Kids array.

[npm, 2016/11/04 19:33:33]

Done.

+  std::vector<std::pair<CPDF_Dictionary*, int>> m_pTreeTraversal;

[Lei Zhang, 2016/11/04 01:38:52]

Should the int also be a size_t here?

[npm, 2016/11/04 19:33:33]

Done.

+  // Index of the next page that will be traversed from the page tree.
+  int m_iNextPageToTraverse;
   bool m_bLinearized;
   int m_iFirstPageNo;
   uint32_t m_dwFirstPageObjNum;