Bug 1856084 - Destroy nsLanguageAtomService even if nsLayoutStatics isn't destroyed. r=platform-i18n-reviewers,dminor

When looking pernos debug session, since `nsLayoutStatics` isn't destroyed,
`nsLanguageAtomService` isn't destroyed. It seems to be some objects are
leaked according to stdout and stderr on debug build.

So we should destroy this service to avoid other debug assertion even if
`nsLayoutStatics` isn't destroyed.

Differential Revision: https://phabricator.services.mozilla.com/D192607

layout/build/nsLayoutStatics.cpp

@@ -47,7 +47,6 @@
 #include "mozilla/dom/HTMLDNSPrefetch.h"
 #include "mozilla/dom/HTMLInputElement.h"
 #include "mozilla/dom/SVGElementFactory.h"
-#include "nsLanguageAtomService.h"
 #include "nsMathMLAtoms.h"
 #include "nsMathMLOperators.h"
 #include "Navigator.h"
@@ -318,7 +317,6 @@ void nsLayoutStatics::Shutdown() {
   HTMLDNSPrefetch::Shutdown();
   nsCSSRendering::Shutdown();
   StaticPresData::Shutdown();
-  nsLanguageAtomService::Shutdown();
 #ifdef DEBUG
   nsIFrame::DisplayReflowShutdown();
 #endif

xpcom/build/XPCOMInit.cpp

@@ -63,6 +63,7 @@
 
 #include "nsAtomTable.h"
 #include "nsISupportsImpl.h"
+#include "nsLanguageAtomService.h"
 
 #include "nsSystemInfo.h"
 #include "nsMemoryReporterManager.h"
@@ -762,6 +763,8 @@ nsresult ShutdownXPCOM(nsIServiceManager* aServMgr) {
   nsComponentManagerImpl::gComponentManager = nullptr;
   nsCategoryManager::Destroy();
 
+  nsLanguageAtomService::Shutdown();
+
   GkRust_Shutdown();
 
 #ifdef NS_FREE_PERMANENT_DATA