Use DPI from Print Preview on Windows, handle non square

printing/print_settings.cc

Index: printing/print_settings.cc
diff --git a/printing/print_settings.cc b/printing/print_settings.cc
index 37233be7ab2010bc181b162caf80c2bf0bd90987..aef18c33bd24e74a12b4ec6f1c3ac1aedf4a2ed5 100644
--- a/printing/print_settings.cc
+++ b/printing/print_settings.cc
@@ -159,7 +159,6 @@ PrintSettings::~PrintSettings() {
 
 void PrintSettings::Clear() {
   ranges_.clear();
-  desired_dpi_ = 72;
   selection_only_ = false;
   margin_type_ = DEFAULT_MARGINS;
   title_.clear();
@@ -173,7 +172,8 @@ void PrintSettings::Clear() {
   device_name_.clear();
   requested_media_ = RequestedMedia();
   page_setup_device_units_.Clear();
-  dpi_ = 0;
+  dpi_[0] = 0;
+  dpi_[1] = 0;
   scale_factor_ = 1.0f;
   rasterize_pdf_ = false;
   landscape_ = false;