There are a few instances of |ifneq (mobile,$(MOZ_BUILD_APP))| in makefiles in browser/* which are obviously redundant.
Two of the three instances are recent, and have been most likely copied from the third (browser/devtools/webconsole/Makefile.in), which original existed in toolkit (http://hg.mozilla.org/mozilla-central/rev/2cf6a6d0f962), where the check was obviously necessary.
Created attachment 575660 [details] [diff] [review]
Thanks for telling us about this, and fixing it. I'm removing bug 582596 and bug 583041 from the blocks lists because they're closed.