Fix security vulnerability am: 2ae83f4f62 am: 11ab583834
am: ac2b87ac0f

Change-Id: I3b249a9ec1820917dc015c72bd093535927c9ed6
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 96a8adb..73ba2e5 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -1982,8 +1982,7 @@
         if (s.client != NULL) {
             sp<IBinder> binder = s.client->asBinder();
             if (binder != NULL) {
-                String16 desc(binder->getInterfaceDescriptor());
-                if (desc == ISurfaceComposerClient::descriptor) {
+                if (binder->queryLocalInterface(ISurfaceComposerClient::descriptor) != NULL) {
                     sp<Client> client( static_cast<Client *>(s.client.get()) );
                     transactionFlags |= setClientStateLocked(client, s.state);
                 }