Bug 1272521 - Hide Widevine CDM on MacOSX 10.6. r=spohl

The Widevine CDM crashes on MacOSX 10.6, so only download, expose, and install
it on 10.7 and later.

MozReview-Commit-ID: 51iJpQEB1m7

--HG--
extra : rebase_source : e24e8d8179f22f77c3e5fbfef8489aca7c4fecb9

toolkit/modules/GMPUtils.jsm

@@ -80,10 +80,9 @@ this.GMPUtils = {
       }
     } else if (aPlugin.id == WIDEVINE_ID) {
       // The Widevine plugin is available for Windows versions Vista and later
-      // and Mac
-      if ((Services.appinfo.OS == "WINNT" &&
-          Services.sysinfo.getPropertyAsInt32("version") >= 6) ||
-          Services.appinfo.OS == "Darwin") {
+      // and Mac OSX 10.7 and later.
+      if (AppConstants.isPlatformAndVersionAtLeast("win", "6") ||
+          AppConstants.isPlatformAndVersionAtLeast("macosx", "10.7")) {
         return true;
       }
       return false;

toolkit/mozapps/extensions/test/browser/browser_gmpProvider.js

@@ -5,6 +5,7 @@
 "use strict";
 
 Cu.import("resource://gre/modules/Promise.jsm");
+Cu.import("resource://gre/modules/AppConstants.jsm");
 var {AddonTestUtils} = Cu.import("resource://testing-common/AddonManagerTesting.jsm", {});
 var GMPScope = Cu.import("resource://gre/modules/addons/GMPProvider.jsm");
 
@@ -386,9 +387,8 @@ add_task(function* testEmeSupport() {
                   "Adobe EME not supported, couldn't find add-on element.");
       }
     } else if (addon.id == GMPScope.WIDEVINE_ID) {
-      if ((Services.appinfo.OS == "WINNT" &&
-          Services.sysinfo.getPropertyAsInt32("version") >= 6) ||
-          Services.appinfo.OS == "Darwin") {
+      if (AppConstants.isPlatformAndVersionAtLeast("win", "6") ||
+          AppConstants.isPlatformAndVersionAtLeast("macosx", "10.7")) {
         Assert.ok(item, "Widevine supported, found add-on element.");
       } else {
         Assert.ok(!item,