Bug 1413166 - Export gtk_csd* atoms as media features, r=bz

Based on patch by Andrew Comminos [:acomminos] <andrew@comminos.com>

MozReview-Commit-ID: 26IV2A3vZAB

--HG--
extra : rebase_source : a4cbcafc8a8e8539b8275e5d0dfdff55175cc882

layout/style/nsMediaFeatures.cpp

@@ -795,6 +795,42 @@ nsMediaFeatures::features[] = {
     GetSystemMetric
   },
 
+  {
+    &nsGkAtoms::_moz_gtk_csd_available,
+    nsMediaFeature::eMinMaxNotAllowed,
+    nsMediaFeature::eBoolInteger,
+    nsMediaFeature::eUserAgentAndChromeOnly,
+    { &nsGkAtoms::gtk_csd_available },
+    GetSystemMetric
+  },
+
+  {
+    &nsGkAtoms::_moz_gtk_csd_minimize_button,
+    nsMediaFeature::eMinMaxNotAllowed,
+    nsMediaFeature::eBoolInteger,
+    nsMediaFeature::eUserAgentAndChromeOnly,
+    { &nsGkAtoms::gtk_csd_minimize_button },
+    GetSystemMetric
+  },
+
+  {
+    &nsGkAtoms::_moz_gtk_csd_maximize_button,
+    nsMediaFeature::eMinMaxNotAllowed,
+    nsMediaFeature::eBoolInteger,
+    nsMediaFeature::eUserAgentAndChromeOnly,
+    { &nsGkAtoms::gtk_csd_maximize_button },
+    GetSystemMetric
+  },
+
+  {
+    &nsGkAtoms::_moz_gtk_csd_close_button,
+    nsMediaFeature::eMinMaxNotAllowed,
+    nsMediaFeature::eBoolInteger,
+    nsMediaFeature::eUserAgentAndChromeOnly,
+    { &nsGkAtoms::gtk_csd_close_button },
+    GetSystemMetric
+  },
+
   // Internal -moz-is-glyph media feature: applies only inside SVG glyphs.
   // Internal because it is really only useful in the user agent anyway
   //  and therefore not worth standardizing.