Eliminate PS printing edge cases

chrome/browser/printing/pdf_to_emf_converter.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/browser/printing/pdf_to_emf_converter.h"
 
 #include <stdint.h>
 #include <windows.h>
 
 #include <memory>
@@ skipping 346 matching lines @@
   // release |file_| before returning.
   Emf emf;
   if (!LoadEmf(&emf)) {
     Close();
     return false;
   }
 
   {
     // Ensure enumerator destruction before calling Close() below.
     Emf::Enumerator emf_enum(emf, nullptr, nullptr);
+
+    // Check if postscript passthrough is supported. Use normal passthrough if
+    // it is not.
+    DWORD escape = POSTSCRIPT_PASSTHROUGH;
+    const char* ptr = reinterpret_cast<const char*>(&escape);
+    bool postscript_passthrough =

[Lei Zhang, 2017/02/25 03:03:35]

int passthrough = ExtEscape(hdc, QUERYESCSUPPORT, sizeof(escape), ptr, 0,
nullptr) > 0 ?  POSTSCRIPT_PASSTHROUGH : PASSTHROUGH;

Then below:

int ret = ExtEscape(hdc, passthrough, 2 + *ptr, data, 0, nullptr);

+        ExtEscape(hdc, QUERYESCSUPPORT, sizeof(escape), ptr, 0, nullptr) > 0;
+
     for (const Emf::Record& record : emf_enum) {
       auto* emf_record = record.record();
       if (emf_record->iType != EMR_GDICOMMENT)
         continue;
 
       const EMRGDICOMMENT* comment =
           reinterpret_cast<const EMRGDICOMMENT*>(emf_record);
       const char* data = reinterpret_cast<const char*>(comment->Data);
       const uint16_t* ptr = reinterpret_cast<const uint16_t*>(data);
-      int ret =
-          ExtEscape(hdc, POSTSCRIPT_PASSTHROUGH, 2 + *ptr, data, 0, nullptr);
+      int ret = 0;
+      if (postscript_passthrough) {
+        ret =
+            ExtEscape(hdc, POSTSCRIPT_PASSTHROUGH, 2 + *ptr, data, 0, nullptr);
+      } else {
+        ret = ExtEscape(hdc, PASSTHROUGH, 2 + *ptr, data, 0, nullptr);
+      }
       DCHECK_EQ(*ptr, ret);
     }
   }
   Close();
   return true;
 }
 
 PdfConverterUtilityProcessHostClient::PdfConverterUtilityProcessHostClient(
     base::WeakPtr<PdfConverterImpl> converter,
     const PdfRenderSettings& settings)
@@ skipping 252 matching lines @@
   std::unique_ptr<PdfConverterImpl> converter =
       base::MakeUnique<PdfConverterImpl>();
   converter->Start(
       new PdfConverterUtilityProcessHostClient(converter->GetWeakPtr(),
                                                conversion_settings),
           data, start_callback);
   return std::move(converter);
 }
 
 }  // namespace printing