Fix crash on shutdown (or patch things up so they don't crash) by releasing memory pressure observers closer to the beginning of XPCOM shutdown. b=47791 r=waterson@netscape.com

xpcom/base/nsMemoryImpl.cpp

@@ -195,12 +195,16 @@ nsMemoryImpl::Startup()
     return Create(nsnull, NS_GET_IID(nsIMemory), (void**)&gMemory);
 }
 
+nsresult 
+nsMemoryImpl::ReleaseObservers()
+{
+    // set mObservers to null to release observers
+    ((nsMemoryImpl*)gMemory)->mObservers = nsnull;
+}
+
 nsresult 
 nsMemoryImpl::Shutdown()
 {
-    // set mObservers to null just to be conservative:
-    ((nsMemoryImpl*)gMemory)->mObservers = nsnull;
-
     NS_RELEASE(gMemory);
     gMemory = nsnull;
     return NS_OK;

xpcom/base/nsMemoryImpl.h

@@ -40,6 +40,7 @@ public:
 
     // called from xpcom initialization/finalization:
     static nsresult Startup();
+    static nsresult ReleaseObservers();
     static nsresult Shutdown();
 
     static NS_METHOD

xpcom/build/nsXPComInit.cpp

@@ -611,6 +611,10 @@ nsresult NS_COM NS_ShutdownXPCOM(nsIServiceManager* servMgr)
     // will cause servicemanager to become inaccessible.
     gShuttingDown = PR_TRUE;
 
+    // Release memory pressure observers now so that things get
+    // released earlier.
+    nsMemoryImpl::ReleaseObservers();
+
     // Release our own singletons...
     XPTI_FreeInterfaceInfoManager();