Fix DCHECK failure in page_setup.cc on Linux.

printing/print_settings_initializer_gtk.cc

 // Copyright (c) 2010 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/print_settings_initializer_gtk.h"
 
 #include <gtk/gtk.h>
 #include <gtk/gtkprinter.h>
 
 #include "base/string_piece.h"
@@ skipping 44 matching lines @@
     // TODO(jhawkins) Remove this hack when the Linux printing refactoring
     // finishes.
     dpi = kPixelsPerInch;
     double page_width_in_pixel = 8.5 * dpi;
     double page_height_in_pixel = 11.0 * dpi;
     physical_size_device_units.SetSize(
       static_cast<int>(page_width_in_pixel),
       static_cast<int>(page_height_in_pixel));
     printable_area_device_units.SetRect(
       static_cast<int>(
-          NativeMetafile::kLeftMarginInInch * printing::kPixelsPerInch),
+          NativeMetafile::kLeftMarginInInch * dpi),
       static_cast<int>(
-          NativeMetafile::kTopMarginInInch * printing::kPixelsPerInch),
-      page_width_in_pixel,
-      page_height_in_pixel);
+          NativeMetafile::kTopMarginInInch * dpi),
+      page_width_in_pixel -
+      (NativeMetafile::kLeftMarginInInch +
+       NativeMetafile::kRightMarginInInch) * dpi,
+      page_height_in_pixel -
+      (NativeMetafile::kTopMarginInInch +
+       NativeMetafile::kBottomMarginInInch) * dpi);
   }
 
   print_settings->set_dpi(dpi);
   print_settings->SetPrinterPrintableArea(physical_size_device_units,
                                           printable_area_device_units,
                                           dpi);
 }
 
 }  // namespace printing