2 files changed, 27 insertions, 0 deletions
diff --git a/core/fpdfapi/page/cpdf_page.cpp b/core/fpdfapi/page/cpdf_page.cpp
index ba30ce57c3..46123ab42e 100644
--- a/core/fpdfapi/page/cpdf_page.cpp
+++ b/core/fpdfapi/page/cpdf_page.cpp
@@ -175,3 +175,13 @@ CFX_Matrix CPDF_Page::GetDisplayMatrix(int xPos,
                            x0, y0));
   return matrix;
 }
+
+bool GraphicsData::operator<(const GraphicsData& other) const {
+  if (fillAlpha != other.fillAlpha)
+    return fillAlpha < other.fillAlpha;
+  return strokeAlpha < other.strokeAlpha;
+}
+
+bool FontData::operator<(const FontData& other) const {
+  return baseFont < other.baseFont;
+}
diff --git a/core/fpdfapi/page/cpdf_page.h b/core/fpdfapi/page/cpdf_page.h
index 6d29a8f34e..9e303562c6 100644
--- a/core/fpdfapi/page/cpdf_page.h
+++ b/core/fpdfapi/page/cpdf_page.h
@@ -7,6 +7,7 @@
 #ifndef CORE_FPDFAPI_PAGE_CPDF_PAGE_H_
 #define CORE_FPDFAPI_PAGE_CPDF_PAGE_H_
 
+#include <map>
 #include <memory>
 
 #include "core/fpdfapi/page/cpdf_pageobjectholder.h"
@@ -20,6 +21,19 @@ class CPDF_Object;
 class CPDF_PageRenderCache;
 class CPDF_PageRenderContext;
 
+// These structs are used to keep track of resources that have already been
+// generated in the page.
+struct GraphicsData {
+  FX_FLOAT fillAlpha;
+  FX_FLOAT strokeAlpha;
+  bool operator<(const GraphicsData& other) const;
+};
+
+struct FontData {
+  CFX_ByteString baseFont;
+  bool operator<(const FontData& other) const;
+};
+
 class CPDF_Page : public CPDF_PageObjectHolder {
  public:
   class View {};  // Caller implements as desired, empty here due to layering.
@@ -52,6 +66,9 @@ class CPDF_Page : public CPDF_PageObjectHolder {
   View* GetView() const { return m_pView; }
   void SetView(View* pView) { m_pView = pView; }
 
+  std::map<GraphicsData, CFX_ByteString> m_GraphicsMap;
+  std::map<FontData, CFX_ByteString> m_FontsMap;
+
  protected:
   void StartParse();