Use file handles to interact with utility process.

chrome/browser/printing/print_job.cc

Index: chrome/browser/printing/print_job.cc
diff --git a/chrome/browser/printing/print_job.cc b/chrome/browser/printing/print_job.cc
index 2569af4ea7743c7727f212f75da4edcab3654da5..9a85ed770800cbc4ab2d7f80429a787aab4b84b5 100644
--- a/chrome/browser/printing/print_job.cc
+++ b/chrome/browser/printing/print_job.cc
@@ -17,6 +17,11 @@
 #include "printing/printed_document.h"
 #include "printing/printed_page.h"
 
+#if defined(OS_WIN)
+#include "chrome/browser/printing/pdf_to_emf_converter.h"
+#include "printing/pdf_render_settings.h"
+#endif
+
 using base::TimeDelta;
 
 namespace {
@@ -37,6 +42,10 @@ PrintJob::PrintJob()
       settings_(),
       is_job_pending_(false),
       is_canceling_(false),
+#if defined(OS_WIN)
+      pdf_to_emf_page_count_(0),
+      pdf_to_emf_current_page_(0),
+#endif
       quit_factory_(this) {
   // This is normally a UI message loop, but in unit tests, the message loop is
   // of the 'default' type.
@@ -214,6 +223,57 @@ PrintedDocument* PrintJob::document() const {
   return document_.get();
 }
 
+#if defined(OS_WIN)
+void PrintJob::ConvertPdfToEmf(
+    const scoped_refptr<base::RefCountedMemory>& bytes,
+    gfx::Size page_size,
+    gfx::Rect content_area) {

[Lei Zhang, 2014/09/15 21:49:53]

Can you DCHECK here and in the callbacks to make sure you are on the right
thread.

[Vitaly Buka (NO REVIEWS), 2014/09/15 22:33:50]

Done.

+  DCHECK(!pdf_to_emf_converter_.get());
+  pdf_to_emf_converter_ = PdfToEmfConverter::CreateDefault();
+  const int kPrinterDpi = settings().dpi();
+  pdf_to_emf_page_size_ = page_size;

[Lei Zhang, 2014/09/15 21:49:53]

This is set once here for PDF file. Is the PDF file guaranteeded to have all
pages be the same size at this point? Arbitrary PDFs can have pages with
different page sizes.

Is the PDF only 1 page when called from PrintViewManagerBase::OnDidPrintPage()
so it doesn't matter in that case?

[Vitaly Buka (NO REVIEWS), 2014/09/15 22:33:50]

That's looks incorrect. 
But I don't change behaivour in this patch. 
Maybe it was regressed when we switched from EMF to PDF for renderer IPC

I'll file but to investigate.
https://code.google.com/p/chromium/issues/detail?id=414477

On 2014/09/15 21:49:53, Lei Zhang wrote:

+  pdf_to_emf_content_area_ = content_area;
+  pdf_to_emf_converter_->Start(
+      bytes,
+      printing::PdfRenderSettings(content_area, kPrinterDpi, true),
+      base::Bind(&PrintJob::OnPdfLoaded, this));
+}
+
+void PrintJob::OnPdfPageConvertedToEmf(int page_number,
+                                       double scale_factor,
+                                       scoped_ptr<MetafilePlayer> emf) {
+  DCHECK(pdf_to_emf_converter_);
+  if (!document_.get() || !emf)
+    return OnPdfLoaded(false);
+
+  // Update the rendered document. It will send notifications to the listener.
+  document_->SetPage(pdf_to_emf_current_page_++,
+                     emf.Pass(),
+                     scale_factor,
+                     pdf_to_emf_page_size_,
+                     pdf_to_emf_content_area_);
+
+  if (pdf_to_emf_current_page_ < pdf_to_emf_page_count_)

[Lei Zhang, 2014/09/15 21:49:53]

nit: wrap inner block in braces.

[Vitaly Buka (NO REVIEWS), 2014/09/15 22:33:50]

Done.

[Vitaly Buka (NO REVIEWS), 2014/09/15 22:33:50]

Done.

+    pdf_to_emf_converter_->GetPage(
+        pdf_to_emf_current_page_,
+        base::Bind(&PrintJob::OnPdfPageConvertedToEmf, this));
+}
+
+void PrintJob::OnPdfLoaded(int page_count) {
+  if (page_count <= 0) {
+    pdf_to_emf_converter_.reset();
+    Cancel();
+    return;
+  }
+  pdf_to_emf_page_count_ = page_count;
+  pdf_to_emf_current_page_ = 0;
+
+  pdf_to_emf_converter_->GetPage(
+      pdf_to_emf_current_page_,
+      base::Bind(&PrintJob::OnPdfPageConvertedToEmf, this));
+}
+#endif  // OS_WIN
+
 void PrintJob::UpdatePrintedDocument(PrintedDocument* new_document) {
   if (document_.get() == new_document)
     return;