Bug 114850: scrollbars permanently hidden when using window.scrollbars.visible = false, patch by Martijn Wargers <martijn.martijn@gmail.com>, r+sr=bzbarsky

dom/src/base/nsBarProps.cpp

@@ -301,6 +301,15 @@ nsScrollbarsProp::GetVisible(PRBool *aVisible)
 NS_IMETHODIMP
 nsScrollbarsProp::SetVisible(PRBool aVisible)
 {
+  PRBool   enabled = PR_FALSE;
+
+  nsCOMPtr<nsIScriptSecurityManager>
+           securityManager(do_GetService(NS_SCRIPTSECURITYMANAGER_CONTRACTID));
+  if (securityManager)
+    securityManager->IsCapabilityEnabled("UniversalBrowserWrite", &enabled);
+  if (!enabled)
+    return NS_OK;
+
   /* Scrollbars, unlike the other barprops, implement visibility directly
      rather than handing off to the superclass (and from there to the
      chrome window) because scrollbar visibility uniquely applies only