From: L. David Baron <dbaron@dbaron.org>

Add an OSX variable to the reftest condition sandbox to make it easier to test Mac OS X versions.

diff --git a/layout/tools/reftest/reftest.js b/layout/tools/reftest/reftest.js
--- a/layout/tools/reftest/reftest.js
+++ b/layout/tools/reftest/reftest.js
@@ -539,16 +539,21 @@ function BuildConditionSandbox(aURL) {
     sandbox.http = { __exposedProps__: {} };
     for each (var prop in [ "userAgent", "appName", "appVersion",
                             "vendor", "vendorSub",
                             "product", "productSub",
                             "platform", "oscpu", "language", "misc" ]) {
         sandbox.http[prop] = hh[prop];
         sandbox.http.__exposedProps__[prop] = "r";
     }
+
+    // Set OSX to the Mac OS X version for Mac, and 0 otherwise.
+    var osxmatch = /^Mac OS X (\d+.\d+)$/.exec(hh.oscpu);
+    sandbox.OSX = osxmatch ? parseFloat(osxmatch[1]) : 0;
+
     // see if we have the test plugin available,
     // and set a sandox prop accordingly
     sandbox.haveTestPlugin = false;
 
     var navigator = gContainingWindow.navigator;
     for (var i = 0; i < navigator.mimeTypes.length; i++) {
         if (navigator.mimeTypes[i].type == "application/x-test" &&
             navigator.mimeTypes[i].enabledPlugin != null &&