Add explicit colordepth test for bug 414720 - Enable 24-bit display on Windows test boxes.

modules/libpr0n/test/reftest/colordepth.html

@@ -0,0 +1,14 @@
+<script>
+/*
+ * Almost all of the image decoding reftests require the display to be in
+ * 24-bit color mode, or else the rendered images will have subtle color
+ * variations and will fail. The Windows test boxes have a tendancy to flip to
+ * 16-bit color mode (see bug 414720), so this test will explicit check the
+ * color depth to make it more obvious when that happens.
+ */
+var colorDepth = window.screen.colorDepth;
+
+if (colorDepth != 24)
+    document.write("ERROR: color depth is " + colorDepth + ".");
+
+</script>

modules/libpr0n/test/reftest/reftest.list

@@ -1,11 +1,11 @@
-#
+# Check for 24-bit color mode (bug 414720)
+== colordepth.html about:blank
+
 # "PngSuite, the official set of PNG test images"
 # Images by Willem van Schaik
 #
 # http://www.schaik.com/pngsuite/pngsuite.html
 # http://www.libpng.org/pub/png/pngsuite.html
-#
-
 include pngsuite-basic-n/reftest.list
 include pngsuite-basic-i/reftest.list
 include pngsuite-ancillary/reftest.list