PageActionLayout is not thread-safe. We touch views off the main thread [1] and touch data structures (such as mPageActionList) on multiple threads [2]. The vast majority of PageActionLayout is UI-related, so the most straightforward way to fix this would be to require that all methods are called on the UI thread like other Android views. [1] http://mxr.mozilla.org/mozilla-central/source/mobile/android/base/toolbar/PageActionLayout.java#167 [2] http://mxr.mozilla.org/mozilla-central/source/mobile/android/base/toolbar/PageActionLayout.java#110

Comment on attachment 8442547 [details] [diff] [review] Only touch PageActionLayout on UI thread Review of attachment 8442547 [details] [diff] [review]: ----------------------------------------------------------------- Can you add some TheadUtils.assertOnUIThread() calls in these methods to ensure that we don't break them?

sorry had to backout this change in https://tbpl.mozilla.org/?tree=Fx-Team&rev=7e6ee365e01c since the first push caused a test failure like: https://tbpl.mozilla.org/php/getParsedLog.php?id=43805525&tree=Fx-Team

Removed second argument from Bundle#getString, which API 12+ only. https://hg.mozilla.org/integration/fx-team/rev/c4185cf15dfd