Bug 1248985 - Fix Spelling Error in nsAppShell.mm. r=josh

MozReview-Commit-ID: LqJrA0UOUfi

--HG--
extra : transplant_source : %7D%08%5C%25%2A6%DD%7F%E0%5D%14R%FA%E8a%9F%A1M%A0%F5

widget/cocoa/nsAppShell.mm

@@ -364,7 +364,7 @@ nsAppShell::ProcessGeckoEvents(void* aInfo)
     // presentable.
     //
     // But _don't_ set windowNumber to '-1' -- that can lead to nasty
-    // wierdness like bmo bug 397039 (a crash in [NSApp sendEvent:] on one of
+    // weirdness like bmo bug 397039 (a crash in [NSApp sendEvent:] on one of
     // these fake events, because the -1 has gotten changed into the number
     // of an actual NSWindow object, and that NSWindow object has just been
     // destroyed).  Setting windowNumber to '0' seems to work fine -- this