Bug 391311 followup - if the chrome registry doesn't initialize correctly, don't crash on destruction, r=Mossop a=beltzner

chrome/src/nsChromeRegistry.cpp

@@ -430,6 +430,7 @@ nsChromeRegistry::OverlayListHash::GetArray(nsIURI* aBase)
 
 nsChromeRegistry::~nsChromeRegistry()
 {
+  if (mPackagesHash.ops)
     PL_DHashTableFinish(&mPackagesHash);
   gChromeRegistry = nsnull;
 }

chrome/src/nsChromeRegistry.h

@@ -94,7 +94,9 @@ public:
   NS_DECL_NSIOBSERVER
 
   // nsChromeRegistry methods:
-  nsChromeRegistry() : mInitialized(PR_FALSE) { }
+  nsChromeRegistry() : mInitialized(PR_FALSE) {
+    mPackagesHash.ops = nsnull;
+  }
   ~nsChromeRegistry();
 
   nsresult Init();