Eliminate PS printing edge cases

chrome/browser/printing/pdf_to_emf_converter.cc

Index: chrome/browser/printing/pdf_to_emf_converter.cc
diff --git a/chrome/browser/printing/pdf_to_emf_converter.cc b/chrome/browser/printing/pdf_to_emf_converter.cc
index f5066dc429f9543446f777ba40154f476c7c4ada..3aeefb11be168a2bf377356d5fefb0c223d54844 100644
--- a/chrome/browser/printing/pdf_to_emf_converter.cc
+++ b/chrome/browser/printing/pdf_to_emf_converter.cc
@@ -364,6 +364,14 @@ bool PostScriptMetaFile::SafePlayback(HDC hdc) const {
   {
     // 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)
@@ -373,8 +381,13 @@ bool PostScriptMetaFile::SafePlayback(HDC hdc) const {
           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);
     }
   }