Use DPI from Print Preview on Windows, handle non square

printing/print_settings.h

Index: printing/print_settings.h
diff --git a/printing/print_settings.h b/printing/print_settings.h
index 592b7b9edf0557e4a828d0d1fc51528ad56026c5..30823b904d04acdca009ce90b8a5aeb118839a69 100644
--- a/printing/print_settings.h
+++ b/printing/print_settings.h
@@ -5,6 +5,7 @@
 #ifndef PRINTING_PRINT_SETTINGS_H_
 #define PRINTING_PRINT_SETTINGS_H_
 
+#include <algorithm>
 #include <string>
 
 #include "base/strings/string16.h"
@@ -98,8 +99,15 @@ class PRINTING_EXPORT PrintSettings {
   }
   const base::string16& device_name() const { return device_name_; }
 
-  void set_dpi(int dpi) { dpi_ = dpi; }
-  int dpi() const { return dpi_; }
+  void set_dpi(int dpi) {
+    dpi_[0] = dpi;
+    dpi_[1] = dpi;
+  }
+  void set_dpi(int dpi_horizontal, int dpi_vertical) {

[Lei Zhang, 2017/04/04 00:03:03]

Can we name this something else to avoid overloading set_dpi()?

[rbpotter, 2017/04/04 00:36:34]

Done.

+    dpi_[0] = dpi_horizontal;
+    dpi_[1] = dpi_vertical;
+  }
+  int dpi() const { return std::min(dpi_[0], dpi_[1]); }
 
   void set_scale_factor(double scale_factor) { scale_factor_ = scale_factor; }
   double scale_factor() const { return scale_factor_; }
@@ -156,6 +164,9 @@ class PRINTING_EXPORT PrintSettings {
   void set_duplex_mode(DuplexMode duplex_mode) { duplex_mode_ = duplex_mode; }
   DuplexMode duplex_mode() const { return duplex_mode_; }
 
+  int dpi_horizontal() const { return dpi_[0]; }

[Lei Zhang, 2017/04/04 00:03:03]

Can we keep these grouped with dpi() above?

[rbpotter, 2017/04/04 00:36:34]

Done.

+  int dpi_vertical() const { return dpi_[1]; }
+
 #if defined(OS_WIN)
   void set_print_text_with_gdi(bool use_gdi) { print_text_with_gdi_ = use_gdi; }
   bool print_text_with_gdi() const { return print_text_with_gdi_; }
@@ -180,10 +191,6 @@ class PRINTING_EXPORT PrintSettings {
   // This permits printing selected pages only.
   PageRanges ranges_;
 
-  // Desired visible dots per inch rendering for output. Printing should be
-  // scaled to ScreenDpi/dpix*desired_dpi.
-  int desired_dpi_;
-
   // Indicates if the user only wants to print the current selection.
   bool selection_only_;
 
@@ -222,7 +229,7 @@ class PRINTING_EXPORT PrintSettings {
   PageSetup page_setup_device_units_;
 
   // Printer's device effective dots per inch in both axis.

[Lei Zhang, 2017/04/04 00:03:03]

Can we add some notes to say the two values can only differ on Windows, and even
then it's rare?

[rbpotter, 2017/04/04 00:36:34]

Done.

-  int dpi_;
+  int dpi_[2];
 
   // Scale factor
   double scale_factor_;