Bug 943849 - [Shared] Fixed headers does not follow correctly the rendered view. r=kats

b2g/app/b2g.js

@@ -856,3 +856,9 @@ pref("osfile.reset_worker_delay", 5000);
 
 // The URL of the Firefox Accounts auth server backend
 pref("identity.fxaccounts.auth.uri", "https://api-accounts.dev.lcip.org/v1");
+
+// APZC preferences.
+//
+// Gaia relies heavily on scroll events for now, so lets fire them
+// more often than the default value (100).
+pref("apz.asyncscroll.throttle", 40);