allow root to call into surfaceflinger

this is useful for running standalone tests
with standalone SurfaceFlinger.

Change-Id: I08d054f6214affa3a777a82765f4e0bd256ba26d
diff --git a/libs/surfaceflinger_client/ISurfaceComposerClient.cpp b/libs/surfaceflinger_client/ISurfaceComposerClient.cpp
index 2cc1f8e..7730eb1 100644
--- a/libs/surfaceflinger_client/ISurfaceComposerClient.cpp
+++ b/libs/surfaceflinger_client/ISurfaceComposerClient.cpp
@@ -157,7 +157,7 @@
      const int pid = ipc->getCallingPid();
      const int uid = ipc->getCallingUid();
      const int self_pid = getpid();
-     if (UNLIKELY(pid != self_pid && uid != AID_GRAPHICS)) {
+     if (UNLIKELY(pid != self_pid && uid != AID_GRAPHICS && uid != 0)) {
          // we're called from a different process, do the real check
          if (!checkCallingPermission(
                  String16("android.permission.ACCESS_SURFACE_FLINGER")))