Use DPI from Print Preview on Windows, handle non square

components/printing/browser/print_manager_utils.cc

 // Copyright 2015 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 "components/printing/browser/print_manager_utils.h"
 #include "components/printing/common/print_messages.h"
 #include "printing/print_settings.h"
 
 namespace printing {
 
 void RenderParamsFromPrintSettings(const PrintSettings& settings,
                                    PrintMsg_Print_Params* params) {
   params->page_size = settings.page_setup_device_units().physical_size();
   params->content_size.SetSize(
       settings.page_setup_device_units().content_area().width(),
       settings.page_setup_device_units().content_area().height());
   params->printable_area.SetRect(
       settings.page_setup_device_units().printable_area().x(),
       settings.page_setup_device_units().printable_area().y(),
       settings.page_setup_device_units().printable_area().width(),
       settings.page_setup_device_units().printable_area().height());
   params->margin_top = settings.page_setup_device_units().content_area().y();
   params->margin_left = settings.page_setup_device_units().content_area().x();
   params->dpi = settings.dpi();
   params->scale_factor = settings.scale_factor();
-  // Currently hardcoded at 72dpi. See PrintSettings' constructor.
-  params->desired_dpi = settings.desired_dpi();
+  params->desired_dpi = settings.desired_dpi_horizontal() > 0
+                            ? settings.desired_dpi_horizontal()
+                            : 72;

[Lei Zhang, 2017/03/31 22:21:13]

Can we leave this file with only getter calls, and move the 72 DPI value into
printing/ ?

[rbpotter, 2017/04/01 00:08:01]

Removed this parameter entirely and used kPointsPerInch instead,
which is what this was actually used for.

   params->rasterize_pdf = settings.rasterize_pdf();
   // Always use an invalid cookie.
   params->document_cookie = 0;
   params->selection_only = settings.selection_only();
   params->supports_alpha_blend = settings.supports_alpha_blend();
   params->should_print_backgrounds = settings.should_print_backgrounds();
   params->display_header_footer = settings.display_header_footer();
   params->title = settings.title();
   params->url = settings.url();
 }
 
 }  // namespace printing