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 1311ddbeb911f30b9ca39335c0b679ec6f711bab..fa389bb10109e438e3df1e44ac1e87150e57ca34 100644
--- a/printing/print_settings.h
+++ b/printing/print_settings.h
@@ -108,6 +108,13 @@ class PRINTING_EXPORT PrintSettings {
   void set_rasterize_pdf(bool rasterize_pdf) { rasterize_pdf_ = rasterize_pdf; }
   bool rasterize_pdf() const { return rasterize_pdf_; }
 
+  void set_desired_dpi(int dpi_horizontal, int dpi_vertical) {
+#if defined(OS_WIN)
+    desired_dpi_[0] = dpi_horizontal;
+    desired_dpi_[1] = dpi_vertical;
+#endif
+  }
+
   void set_supports_alpha_blend(bool supports_alpha_blend) {
     supports_alpha_blend_ = supports_alpha_blend;
   }
@@ -157,7 +164,8 @@ class PRINTING_EXPORT PrintSettings {
   void set_duplex_mode(DuplexMode duplex_mode) { duplex_mode_ = duplex_mode; }
   DuplexMode duplex_mode() const { return duplex_mode_; }
 
-  int desired_dpi() const { return desired_dpi_; }
+  int desired_dpi_horizontal() const { return desired_dpi_[0]; }
+  int desired_dpi_vertical() const { return desired_dpi_[1]; }
 
 #if defined(OS_WIN)
   void set_print_text_with_gdi(bool use_gdi) { print_text_with_gdi_ = use_gdi; }
@@ -185,7 +193,7 @@ class PRINTING_EXPORT PrintSettings {
 
   // Desired visible dots per inch rendering for output. Printing should be

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

Observation: From what I can tell, this was only used to tell the renderer how
to scale the image in ComputeWebKitPrintParamsInDesiredDpi(), and it was hard
coded to 72.

[rbpotter, 2017/04/01 00:08:02]

Removed it.

   // scaled to ScreenDpi/dpix*desired_dpi.
-  int desired_dpi_;
+  int desired_dpi_[2];
 
   // Indicates if the user only wants to print the current selection.
   bool selection_only_;