Add generic text printing

chrome/utility/printing_handler.cc

 // Copyright 2014 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.
 
 #include "chrome/utility/printing_handler.h"
 
 #include <stdint.h>
 #include <utility>
 
 #include "base/files/file_util.h"
@@ skipping 73 matching lines @@
   return handled;
 }
 
 #if defined(OS_WIN)
 void PrintingHandler::OnRenderPDFPagesToMetafile(
     IPC::PlatformFileForTransit pdf_transit,
     const PdfRenderSettings& settings) {
   pdf_rendering_settings_ = settings;
   chrome_pdf::SetPDFUseGDIPrinting(pdf_rendering_settings_.mode ==
                                    PdfRenderSettings::Mode::GDI_TEXT);
-  int postscript_level;
+  int printing_mode;
   switch (pdf_rendering_settings_.mode) {
+    case PdfRenderSettings::Mode::TEXTONLY:
+      printing_mode = 1;

[Lei Zhang, 2017/07/12 00:21:15]

If you add another enum in pdf/pdf.h and change SetPDFUsePrintMode() to use that
enum as its parameter, then you can use those enum values here instead of these
magical values. Inside pdf/pdfium, you can static_assert() those enum values
match up with FPDF_PRINTMODE_* from PDFium.

Previously, having postscript_level = 2 made sense without needing an enum.

[rbpotter, 2017/07/13 18:46:15]

Done.

+      break;
     case PdfRenderSettings::Mode::POSTSCRIPT_LEVEL2:
-      postscript_level = 2;
+      printing_mode = 2;
       break;
     case PdfRenderSettings::Mode::POSTSCRIPT_LEVEL3:
-      postscript_level = 3;
+      printing_mode = 3;
       break;
     default:
-      postscript_level = 0;  // Not using postscript.
+      printing_mode = 0;  // Not using postscript or text only.
   }
-  chrome_pdf::SetPDFPostscriptPrintingLevel(postscript_level);
+  chrome_pdf::SetPDFUsePrintMode(printing_mode);
 
   base::File pdf_file = IPC::PlatformFileForTransitToFile(pdf_transit);
   int page_count = LoadPDF(std::move(pdf_file));
   Send(
       new ChromeUtilityHostMsg_RenderPDFPagesToMetafiles_PageCount(page_count));
 }
 
 void PrintingHandler::OnRenderPDFPagesToMetafileGetPage(
     int page_number,
     IPC::PlatformFileForTransit output_file) {
@@ skipping 219 matching lines @@
         printer_name, printer_info));
   } else {
     Send(new ChromeUtilityHostMsg_GetPrinterSemanticCapsAndDefaults_Failed(
         printer_name));
   }
   ReleaseProcessIfNeeded();
 }
 #endif  // BUILDFLAG(ENABLE_PRINT_PREVIEW)
 
 }  // namespace printing