Support GC API in nightly builds

[whimboo]

The Garbage Collector API has been landed and we should support it:
https://bugzilla.mozilla.org/show_bug.cgi?id=531396

[whimboo]

See https://bug531396.bugzilla.mozilla.org/attachment.cgi?id=605977 for an example implementation.

[dglol]

This should be top priority since this evening's (3.14) nightly build is not supported by memchaser.

[whimboo]

What do you mean with not supported by memchaser? We have not stopped sending data via the console service. So the GC messages are clearly broken now:

GC(T+0.0) T

Please file a bug for Firefox in Core:Javascript Engine, so it can be fixed.

[dglol]

Bug has been filed: https://bugzilla.mozilla.org/show_bug.cgi?id=735994

[terrence2]

Bug should be fixed now. Sorry for the bustage.

[dglol]

Thanks for fixing the bug @terrence2!
There's just one more problem and that's our regex is broken in FF14 due to the fact that TotalTime is now Total Time. Do you know if this was intentional?

[whimboo]

I hope that this is only a failure. Changing keys in each version is kinda for us to keep up with support across branches. I will comment on the bug.

[whimboo]

Hm, looks like this was intentional. :S So we should once again update our extension and release a minor version.

[whimboo]

We will release version 0.2.1 of memchaser today which keeps track of the changes in the console message. See #94 and #92. It doesn't contain any code to use the observer notifications.

[terrence2]

Added another patch for memchaser to the bugzilla bug. This one supports both old and new browsers and should apply cleanly against master. I'll see about formatting it as a pull request after lunch.

[dglol]

Services.jsm (resource://gre/modules/Services.jsm) supports the observer service so I believe you can reuse some of the code. Other than that, it looks good!

NIT: I probably would have checked for the app version (config.APP_BRANCH) instead of using the property "service" to indicate when the observer service is needed.

[terrence2]

Ah, yes, checking the config version directly should be fine here.

Could you elaborate on what you mean with your first comment? I see that memchaser is doing a Components.utils.import on the jsm you mentioned, but I'm not sure how (or if) it interacts with Components.classes[].getService. Trying to just do Services.addObserver(...) results in an error, so I'm guessing it's more complicated than that. Sorry for being clueless, this is the first time I've looked at a Firefox add-on. :-)

[dglol]

The ObserverService is expose in the initTable of Services.jsm so the usage would be Services.obs.addObserver(...) instead.

Also, another thing to note is that the Components.* objects can be replaced with their initials (as long as it has been intialized). For example, you can use Cc for Components.classes, Ci for Compontents.interfaces, etc.

[whimboo]

Now merged via pull #99