SurfaceFlinger now runs in the process's main thread

it used to spawn its own thread and return the main thread
to the binder thread pool -- this was confusing the naming
of things in the kernel.

Bug: 10331839

Change-Id: I2d13a6d73409a38109300fcbe6a04b4c41cb5d00
diff --git a/services/surfaceflinger/DisplayDevice.h b/services/surfaceflinger/DisplayDevice.h
index 8e24df7..eec0396 100644
--- a/services/surfaceflinger/DisplayDevice.h
+++ b/services/surfaceflinger/DisplayDevice.h
@@ -26,6 +26,7 @@
 #include <EGL/eglext.h>
 
 #include <utils/Mutex.h>
+#include <utils/String8.h>
 #include <utils/Timers.h>
 
 #include <hardware/hwcomposer_defs.h>