Use file handles to interact with utility process.

chrome/utility/printing_handler.h

Index: chrome/utility/printing_handler.h
diff --git a/chrome/utility/printing_handler.h b/chrome/utility/printing_handler.h
index d0135f5b2ba84f7be5e34ec46b654aef0854cd6c..db0194d51f8d6035427ae790202d2c8b6be40068 100644
--- a/chrome/utility/printing_handler.h
+++ b/chrome/utility/printing_handler.h
@@ -9,6 +9,7 @@
 #include "base/macros.h"
 #include "chrome/utility/utility_message_handler.h"
 #include "ipc/ipc_platform_file.h"
+#include "printing/pdf_render_settings.h"
 
 #if !defined(ENABLE_FULL_PRINTING) && !defined(OS_WIN)
 #error "Windows or full printing must be enabled"
@@ -34,11 +35,12 @@ class PrintingHandler : public UtilityMessageHandler {
  private:
   // IPC message handlers.
 #if defined(OS_WIN)
-  void OnRenderPDFPagesToMetafile(
-      IPC::PlatformFileForTransit pdf_transit,
-      const base::FilePath& metafile_path,
-      const printing::PdfRenderSettings& settings,
-      const std::vector<printing::PageRange>& page_ranges);
+  void OnRenderPDFPagesToMetafile(IPC::PlatformFileForTransit pdf_transit,
+                                  const printing::PdfRenderSettings& settings);
+  void OnRenderPDFPagesToMetafileGetPage(
+      int page_number,
+      IPC::PlatformFileForTransit output_file);
+  void OnRenderPDFPagesToMetafileStop();
 #endif  // OS_WIN
 #if defined(ENABLE_FULL_PRINTING)
   void OnRenderPDFPagesToPWGRaster(
@@ -49,18 +51,10 @@ class PrintingHandler : public UtilityMessageHandler {
 #endif  // ENABLE_FULL_PRINTING
 
 #if defined(OS_WIN)
-  // Helper method for Windows.
-  // |highest_rendered_page_number| is set to -1 on failure to render any page.
-  // |page_ranges| is both input and output. If supplied as input, only the
-  // specified pages will be rendered. If an empty vector is supplied it will
-  // be filled with a range of all pages that were rendered.
-  bool RenderPDFToWinMetafile(
-      base::File pdf_file,
-      const base::FilePath& metafile_path,
-      const printing::PdfRenderSettings& settings,
-      std::vector<printing::PageRange>* page_ranges,
-      int* highest_rendered_page_number,
-      double* scale_factor);
+  int LoadPDF(base::File pdf_file);
+  bool RenderPdfPageToMetafile(int page_number,
+                               base::File output_file,
+                               double* scale_factor);
 #endif  // OS_WIN
 #if defined(ENABLE_FULL_PRINTING)
   bool RenderPDFPagesToPWGRaster(
@@ -73,6 +67,11 @@ class PrintingHandler : public UtilityMessageHandler {
   void OnGetPrinterSemanticCapsAndDefaults(const std::string& printer_name);
 #endif  // ENABLE_FULL_PRINTING
 
+#if defined(OS_WIN)
+  std::vector<char> pdf_data_;
+  printing::PdfRenderSettings pdf_rendering_settings_;
+#endif
+
   DISALLOW_COPY_AND_ASSIGN(PrintingHandler);
 };