1960748 - Re-enable low memory detection in Android/GeckoView tests

Status: NEW

(GeckoView :: General, task, P3)

Description

[Gabriele Svelto [:gsvelto]]

Bug 1959681 will disable the low-memory detection in GeckoView to reduce the number of intermittents caused by memory-pressure events causing visible changes that the tests are not prepared to handle. However we'd like to have that enabled in the long run, since it might unearth actual issues that the users might experience. There's a few things that need to be done in order to re-enable it though:

• All the native sites listening to memory-pressure events and the Java/Kotlin sites using onTrimMemory() need to be audited to check which visible effects they may have. One known one is that tabs might be unloaded.
• We should run the Android tests a significant number of times with low-memory detection enabled to identify the potential intermittent failures that need to be fixed.
• Once we've identified the tests that are failing we have three courses of action: fix the test to accommodate for the visible effects of memory-pressure events, selectively disable low-memory detection for that particular test if it's impossible to fix or change the memory-pressure/onTrimMemory listener that is causing the problem (the latter is likely going to happen only as a last resort if something is demonstrably broken)

Additionally we might want to deliberately send low memory notifications in chaos mode, to increase the chance of it breaking tests.