Revert "Discard framebuffer rendering queues when discarding layers"

This reverts commit da96f8ac2c1c35a54f3f36e6d776cb386a251d03.
diff --git a/libs/hwui/Android.mk b/libs/hwui/Android.mk
index 95e0a18..9bfc94c 100644
--- a/libs/hwui/Android.mk
+++ b/libs/hwui/Android.mk
@@ -38,7 +38,7 @@
 		external/skia/src/ports \
 		external/skia/include/utils
 
-	LOCAL_CFLAGS += -DUSE_OPENGL_RENDERER -DGL_GLEXT_PROTOTYPES
+	LOCAL_CFLAGS += -DUSE_OPENGL_RENDERER
 	LOCAL_CFLAGS += -fvisibility=hidden
 	LOCAL_MODULE_CLASS := SHARED_LIBRARIES
 	LOCAL_SHARED_LIBRARIES := libcutils libutils libGLESv2 libskia libui