773836 - Remove MemoryObserver from browser.js

Status: RESOLVED FIXED

(Firefox for Metro Graveyard :: General, defect)

Description

[Jonathan Wilde [:jwilde]]

MemoryObserver.observe <http://hg.mozilla.org/projects/elm/file/8e164efe3de9/browser/metro/base/content/browser.js#l2392> is used to force GC from JavaScript when the device is very low on memory.  The observe function, when run on the Samsung Series 7, locks the UI for ~2.5 seconds.

Under debug mode, when you press Control-F, it'll run that function <http://hg.mozilla.org/projects/elm/file/8e164efe3de9/browser/metro/base/content/browser.js#l71>, locking the UI for ~2.5 seconds and then eventually showing the find-in-page widget.

As jimm pointed out on <https://bugzilla.mozilla.org/show_bug.cgi?id=773471#c2>, MemoryObserver is specifically intended for memory-constrained environments, so we should be able to safely remove this.

Comment 1

[Jonathan Wilde [:jwilde]]

http://hg.mozilla.org/projects/elm/rev/db7587b6e1f3

Comment 2

[Matt Brubeck (:mbrubeck)]

Resolving bugs in the Firefox for Metro product that are fixed on the elm branch.  Sorry for the bugspam.  Search your email for "bugspam-elm" if you want to find and delete all of these messages at once.