Remove stl_util's deletion function use from pdf/.

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 602 matching lines @@
   // The current text used for searching.
   std::string current_find_text_;
 
   // The PDFium wrapper object for the document.
   FPDF_DOCUMENT doc_;
 
   // The PDFium wrapper for form data.  Used even if there are no form controls
   // on the page.
   FPDF_FORMHANDLE form_;
 
-  // The page(s) of the document. Store a vector of pointers so that when the
-  // vector is resized we don't close the pages that are used in pending
-  // paints.
-  std::vector<PDFiumPage*> pages_;
+  // The page(s) of the document.
+  std::vector<std::unique_ptr<PDFiumPage>> pages_;
 
   // The indexes of the pages currently visible.
   std::vector<int> visible_pages_;
 
   // The indexes of the pages pending download.
   std::vector<int> pending_pages_;
 
   // During handling of input events we don't want to unload any pages in
   // callbacks to us from PDFium, since the current page can change while PDFium
   // code still has a pointer to it.
@@ skipping 153 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_