814240 - Weird behaviour of CachingObserversManager when no observer registered

Status: NEW

(Core :: Hardware Abstraction Layer (HAL), defect)

Description

[Chiajung Hung [:chiajung]]

If I never register a observer, I will always get an unreasonable value from CachingObserversManager::GetCurrentInformation().

For example, if I do not register a ScreenConfigurationObserver from a content process and occasionally call hal::GetCurrentScreenConfiguration(). The return value would be fixed to the state when I first call to it. No matter what the real orientation is.

This can only happen if I use these HAL functions from C++ code (e.g. from Gecko). Since there is no permission check or no warning. When I did that, I expect it should returns the up-to-date value, but it didn't.

I think we may need some kind of warning or have to prohibit such usage in an explicit way.