Bug 1234099 - Backout 34460cc654ca due to playback failures caused by Adobe GMP. r=backout

toolkit/modules/GMPUtils.jsm

@@ -81,6 +81,14 @@ this.GMPUtils = {
       return false;
     }
 
+    if (Services.sysinfo.getPropertyAsInt32("version") < 6) {
+      // Windows versions before Vista are unsupported.
+      this.maybeReportTelemetry(aPlugin.id,
+                                "VIDEO_EME_ADOBE_UNSUPPORTED_REASON",
+                                GMPPluginUnsupportedReason.WINDOWS_VERSION);
+      return false;
+    }
+
     return true;
   },
 

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

@@ -378,7 +378,8 @@ add_task(function* testEmeSupport() {
     let doc = gManagerWindow.document;
     let item = get_addon_element(gManagerWindow, addon.id);
     if (addon.id == GMPScope.EME_ADOBE_ID) {
-      if (Services.appinfo.OS == "WINNT") {
+      if (Services.appinfo.OS == "WINNT" &&
+          Services.sysinfo.getPropertyAsInt32("version") >= 6) {
         Assert.ok(item, "Adobe EME supported, found add-on element.");
       } else {
         Assert.ok(!item,