[Printing] Change non-square DPI to non-square pixels

It is not the DPI that is non-square. It is the pixels that are
non-square. Change all references to non-square DPI to non-square
pixels.

Change-Id: I6898de9ded7a21bce5835834f5f8ba5bc6093716
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4616147
Reviewed-by: Alan Screen <awscreen@chromium.org>
Code-Coverage: Findit <findit-for-me@appspot.gserviceaccount.com>
Reviewed-by: Nigi <nigi@chromium.org>
Commit-Queue: Andy Phan <andyphan@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1157892}

pdf/pdfium/pdfium_print.cc

@@ -379,8 +379,8 @@ ScopedFPDFDocument PDFiumPrint::CreateSinglePageRasterPdf(
   float source_page_width = FPDF_GetPageWidthF(page_to_print);
   float source_page_height = FPDF_GetPageHeightF(page_to_print);
 
-  // For computing size in pixels, use a square dpi since the source PDF page
-  // has square DPI.
+  // For computing size in pixels, use square pixels since the source PDF page
+  // has square pixels.
   int width_in_pixels = ConvertUnit(source_page_width, kPointsPerInch, dpi);
   int height_in_pixels = ConvertUnit(source_page_height, kPointsPerInch, dpi);
 

printing/backend/print_backend_win.cc

@@ -136,8 +136,8 @@ gfx::Rect LoadPaperPrintableAreaUm(const wchar_t* printer, DEVMODE* devmode) {
   gfx::Rect printable_area_device_units =
       GetPrintableAreaDeviceUnits(hdc.get());
 
-  // Device units can be non-square, so scale for non-square DPIs and convert to
-  // microns.
+  // Device units can be non-square, so scale for non-square pixels and convert
+  // to microns.
   gfx::Rect printable_area_um =
       gfx::Rect(ConvertUnit(printable_area_device_units.x(),
                             default_dpi.width(), kMicronsPerInch),

printing/print_settings.cc

@@ -507,7 +507,7 @@ void PrintSettings::UpdatePrinterPrintableArea(
     const gfx::Rect& printable_area_um) {
   // Scale the page size and printable area to device units.
   // Blink doesn't support different dpi settings in X and Y axis. Because of
-  // this, printers with non-square DPIs still scale page size and printable
+  // this, printers with non-square pixels still scale page size and printable
   // area using device_units_per_inch() instead of their respective dimensions
   // in device_units_per_inch_size().
   float scale = static_cast<float>(device_units_per_inch()) / kMicronsPerInch;

printing/print_settings_conversion.cc

@@ -102,7 +102,7 @@ void SetPrintableAreaIfValid(PrintSettings& settings,
 
   // Scale the page size and printable area to device units.
   // Blink doesn't support different dpi settings in X and Y axis. Because of
-  // this, printers with non-square DPIs still scale page size and printable
+  // this, printers with non-square pixels still scale page size and printable
   // area using device_units_per_inch() instead of their respective dimensions
   // in device_units_per_inch_size().
   float scale =

printing/print_settings_conversion_unittest.cc

@@ -93,7 +93,7 @@ const char kPrinterSettingsWithImageableArea[] = R"({
 })";
 
 #if !BUILDFLAG(IS_MAC)
-const char kPrinterSettingsWithNonSquareDpi[] = R"({
+const char kPrinterSettingsWithNonSquarePixels[] = R"({
   "headerFooterEnabled": false,
   "title": "Test Doc",
   "url": "http://localhost/",
@@ -273,14 +273,14 @@ TEST(PrintSettingsConversionTest, WithCustomMarginsAndImageableArea) {
 }
 
 #if !BUILDFLAG(IS_MAC)
-TEST(PrintSettingsConversionTest, WithNonSquareDpi) {
+TEST(PrintSettingsConversionTest, WithNonSquarePixels) {
   // Check that physical size and printable area are scaled by the max DPI
-  // value. Not needed for macOS, which always has a square DPI.
+  // value. Not needed for macOS, which always has square pixels.
   static constexpr gfx::Size kExpectedSize{6614, 9354};
   static constexpr gfx::Rect kExpectedPrintableArea{0, 0, 5669, 9323};
 
   base::Value::Dict dict =
-      base::test::ParseJsonDict(kPrinterSettingsWithNonSquareDpi);
+      base::test::ParseJsonDict(kPrinterSettingsWithNonSquarePixels);
   std::unique_ptr<PrintSettings> settings = PrintSettingsFromJobSettings(dict);
   ASSERT_TRUE(settings);
   EXPECT_EQ(settings->dpi_horizontal(), 800);