Revert of Remove some dead PDF code.

pdf/pdfium/pdfium_engine.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef PDF_PDFIUM_PDFIUM_ENGINE_H_
 #define PDF_PDFIUM_PDFIUM_ENGINE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 59 matching lines @@
                           const PP_PrintSettings_Dev& print_settings) override;
   void PrintEnd() override;
   void StartFind(const std::string& text, bool case_sensitive) override;
   bool SelectFindResult(bool forward) override;
   void StopFind() override;
   void ZoomUpdated(double new_zoom_level) override;
   void RotateClockwise() override;
   void RotateCounterclockwise() override;
   std::string GetSelectedText() override;
   std::string GetLinkAtPosition(const pp::Point& point) override;
+  bool IsSelecting() override;
   bool HasPermission(DocumentPermission permission) const override;
   void SelectAll() override;
   int GetNumberOfPages() override;
   pp::VarArray GetBookmarks() override;
   int GetNamedDestinationPage(const std::string& destination) override;
+  int GetFirstVisiblePage() override;
   int GetMostVisiblePage() override;
   pp::Rect GetPageRect(int index) override;
   pp::Rect GetPageContentsRect(int index) override;
   pp::Rect GetPageScreenRect(int page_index) const override;
   int GetVerticalScrollbarYPosition() override { return position_.y(); }
+  void PaintThumbnail(pp::ImageData* image_data, int index) override;
   void SetGrayscale(bool grayscale) override;
   void OnCallback(int id) override;
   std::string GetPageAsJSON(int index) override;
   bool GetPrintScaling() override;
   int GetCopiesToPrint() override;
   int GetDuplexType() override;
   bool GetPageSizeAndUniformity(pp::Size* size) override;
   void AppendBlankPages(int num_pages) override;
   void AppendPage(PDFEngine* engine, int index) override;
   pp::Point GetScrollPosition() override;
@@ skipping 560 matching lines @@
   pp::Size default_page_size_;
 
   // Used to manage timers that form fill API needs.  The pair holds the timer
   // period, in ms, and the callback function.
   std::map<int, std::pair<int, TimerCallback> > timers_;
   int next_timer_id_;
 
   // Holds the page index of the last page that the mouse clicked on.
   int last_page_mouse_down_;
 
+  // Holds the page index of the first visible page; refreshed by calling
+  // CalculateVisiblePages()
+  int first_visible_page_;
+
   // Holds the page index of the most visible page; refreshed by calling
   // CalculateVisiblePages()
   int most_visible_page_;
 
   // Set to true after FORM_DoDocumentJSAction/FORM_DoDocumentOpenAction have
   // been called. Only after that can we call FORM_DoPageAAction.
   bool called_do_document_action_;
 
   // Records parts of form fields that need to be highlighted at next paint, in
   // screen coordinates.
@@ skipping 68 matching lines @@
   bool GetPDFPageSizeByIndex(const void* pdf_buffer,
                              int pdf_buffer_size,
                              int page_number,
                              double* width,
                              double* height) override;
 };
 
 }  // namespace chrome_pdf
 
 #endif  // PDF_PDFIUM_PDFIUM_ENGINE_H_