Printing: Load the source PDF only once.

pdf/pdfium/pdfium_engine.h

Index: pdf/pdfium/pdfium_engine.h
diff --git a/pdf/pdfium/pdfium_engine.h b/pdf/pdfium/pdfium_engine.h
index 0334a602433e801f199023f35b8f4e31e03e6837..4795b16ac359bc4d175825005caf9c27fdef4d59 100644
--- a/pdf/pdfium/pdfium_engine.h
+++ b/pdf/pdfium/pdfium_engine.h
@@ -771,8 +771,7 @@ class PDFiumEngineExports : public PDFEngineExports {
 
 // PDFEngineExports:
 #if defined(OS_WIN)
-  bool RenderPDFPageToDC(const void* pdf_buffer,
-                         int buffer_size,
+  bool RenderPDFPageToDC(void* pdf_handle,
                          int page_number,
                          const RenderingSettings& settings,
                          HDC dc) override;
@@ -781,17 +780,17 @@ class PDFiumEngineExports : public PDFEngineExports {
 
   void SetPDFUseGDIPrinting(bool enable) override;
 #endif  // defined(OS_WIN)
-  bool RenderPDFPageToBitmap(const void* pdf_buffer,
-                             int pdf_buffer_size,
+  bool RenderPDFPageToBitmap(void* pdf_handle,
                              int page_number,
                              const RenderingSettings& settings,
                              void* bitmap_buffer) override;
   bool GetPDFDocInfo(const void* pdf_buffer,
                      int buffer_size,
                      int* page_count,
-                     double* max_page_width) override;
-  bool GetPDFPageSizeByIndex(const void* pdf_buffer,
-                             int pdf_buffer_size,
+                     double* max_page_width,
+                     void** pdf_handle) override;
+  void ReleasePDFHandle(void* pdf_handle) override;
+  bool GetPDFPageSizeByIndex(void* pdf_handle,
                              int page_number,
                              double* width,
                              double* height) override;