I just landed bug 781274 that will opt into Android's Strict Mode
"screen flashing". This testing feature displays a red border when
Fennec calls Android APIs on the UI thread that can cause long UI delays
(such as file or network I/O).
Here is a screenshot of StrictMode's red border:
This only affects "unoffical" builds (local, Nightly, and Aurora
channels) running on Android >= Honeycomb.
The red borders will probably be intermittent, but they should be filed
as UI bugs. Fennec will dump useful debug info to logcat after flashing
If the red borders are causing excessive failures of automated UI tests
or people think they are inappropriately aggressive, then I can disable