Printing: Push checking of |context| one level lower, as the different

printing/printing_context_win.cc

 // Copyright (c) 2009 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 "printing/printing_context.h"
 
 #include <winspool.h>
 
 #include "base/file_util.h"
 #include "base/i18n/file_util_icu.h"
@@ skipping 283 matching lines @@
 
 #ifndef NDEBUG
   page_number_ = 0;
 #endif
   return OK;
 }
 
 PrintingContext::Result PrintingContext::NewPage() {
   if (abort_printing_)
     return CANCEL;
+
+  DCHECK(context_);
   DCHECK(in_print_job_);
 
   // Inform the driver that the application is about to begin sending data.
   if (StartPage(context_) <= 0)
     return OnError();
 
 #ifndef NDEBUG
   ++page_number_;
 #endif
 
@@ skipping 297 matching lines @@
   if (buf_size) {
     buffer->reset(new uint8[buf_size]);
     memset(buffer->get(), 0, buf_size);
     if (!GetPrinter(printer, level, buffer->get(), buf_size, &buf_size)) {
       buffer->reset();
     }
   }
 }
 
 }  // namespace printing