Bug 1110928, first request GC should be a full GC, r=jonco

--HG--
extra : rebase_source : 6949e66d52d5ab4f75bf2a1875e50c49465f5818

dom/base/nsJSEnvironment.cpp

@@ -2260,7 +2260,7 @@ mozilla::dom::StartupJSEnvironment()
   sLikelyShortLivingObjectsNeedingGC = 0;
   sPostGCEventsToConsole = false;
   sNeedsFullCC = false;
-  sNeedsFullGC = false;
+  sNeedsFullGC = true;
   sNeedsGCAfterCC = false;
   gNameSpaceManager = nullptr;
   sContext = nullptr;