Make PluginInstance::PrintPDFOutput-metafile implementation agnostic on Linux.

printing/pdf_ps_metafile_cairo_unittest.cc

 // Copyright (c) 2011 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/pdf_ps_metafile_cairo.h"
 
 #include <fcntl.h>
 #include <string>
 #include <vector>
 
@@ skipping 15 matching lines @@
 
 namespace printing {
 
 TEST_F(PdfPsTest, Pdf) {
   // Tests in-renderer constructor.
   printing::PdfPsMetafile pdf;
   EXPECT_TRUE(pdf.Init());
 
   // Renders page 1.
   EXPECT_TRUE(pdf.StartPage(gfx::Size(72, 73), gfx::Point(4, 5), 1));
-  EXPECT_EQ(printing::PdfPsMetafile::FromCairoContext(pdf.context()), &pdf);
   // In theory, we should use Cairo to draw something on |context|.
   EXPECT_TRUE(pdf.FinishPage());
 
   // Renders page 2.
   EXPECT_TRUE(pdf.StartPage(gfx::Size(72, 73), gfx::Point(4, 5), 1));
   // In theory, we should use Cairo to draw something on |context|.
   EXPECT_TRUE(pdf.FinishPage());
 
   // Closes the file.
   pdf.FinishDocument();
@@ skipping 30 matching lines @@
   EXPECT_TRUE(pdf3.FinishPage());
   pdf3.FinishDocument();
   size = pdf3.GetDataSize();
   EXPECT_EQ(test_raw_data.size(), size);
   std::string output;
   pdf3.GetData(WriteInto(&output, size + 1), size);
   EXPECT_EQ(test_raw_data, output);
 }
 
 }  // namespace printing