Return information about whether overlays are disabled.

Change-Id: I85ae42e9f28461f5142cc6b3c8e25ff3f195805a
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index ff70ec3..5535699 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -1753,6 +1753,7 @@
                 reply->writeInt32(0);
                 reply->writeInt32(mDebugRegion);
                 reply->writeInt32(mDebugBackground);
+                reply->writeInt32(mDebugDisableHWC);
                 return NO_ERROR;
             case 1013: {
                 Mutex::Autolock _l(mStateLock);