Change scoped_ptr to a type alias for std::unique_ptr on OS_WIN

printing/backend/printing_info_win.h

Index: printing/backend/printing_info_win.h
diff --git a/printing/backend/printing_info_win.h b/printing/backend/printing_info_win.h
index c91d837724935c352d36861faca9531ffce88346..896ed12a763be49d43e5cee6baa25431ed0a0c8d 100644
--- a/printing/backend/printing_info_win.h
+++ b/printing/backend/printing_info_win.h
@@ -26,7 +26,7 @@ class PrinterInfo {
  public:
   bool Init(HANDLE printer) {
     buffer_.reset(GetPrinterInfo(printer, level));
-    return buffer_;
+    return buffer_ != nullptr;
   }
 
   const PrinterInfoType* get() const {
@@ -44,7 +44,7 @@ class DriverInfo {
  public:
   bool Init(HANDLE printer) {
     buffer_.reset(GetDriverInfo(printer, level));
-    return buffer_;
+    return buffer_ != nullptr;
   }
 
   const DriverInfoType* get() const {