Create constant variables kPointsPerInch and kPixelsPerInch and conversion functions.

BUG=47277
TEST=units_unittest.cc

Review URL: http://codereview.chromium.org/2877001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@50968 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 14 insertions, 0 deletions

diff --git a/printing/units.h b/printing/units.h
index d23e268..cc61241 100644
--- a/printing/units.h
+++ b/printing/units.h
@@ -10,6 +10,14 @@ namespace printing {
 // Length of a thousanth of inches in 0.01mm unit.
 const int kHundrethsMMPerInch = 2540;
 
+// Length of an inch in CSS's 1pt unit.
+// http://dev.w3.org/csswg/css3-values/#absolute-length-units-cm-mm.-in-pt-pc
+const int kPointsPerInch = 72;
+
+// Length of an inch in CSS's 1px unit.
+// http://dev.w3.org/csswg/css3-values/#the-px-unit
+const int kPixelsPerInch = 96;
+
 // Converts from one unit system to another using integer arithmetics.
 int ConvertUnit(int value, int old_unit, int new_unit);
 
@@ -22,6 +30,12 @@ int ConvertMilliInchToHundredThousanthMeter(int milli_inch);
 // Converts from 0.00001 meter unit to 0.001 inch.
 int ConvertHundredThousanthMeterToMilliInch(int cmm);
 
+// Converts from 1 pixel to 1 point using integers.
+int ConvertPixelsToPoint(int pixels);
+
+// Converts from 1 pixel to 1 point using doubles.
+double ConvertPixelsToPointDouble(double pixels);
+
 }  // namespace printing
 
 #endif  // PRINTING_UNITS_H_