surfaceflinger: refactor FrambufferSurface

This change refactors the FramebufferSurface class to inherit from the new
ConsumerBase class.

Bug: 6620200
Change-Id: I46ec942ddb019658e3c5e79465548b171b2261f2
diff --git a/libs/gui/Android.mk b/libs/gui/Android.mk
index 7006957..3aa3a50 100644
--- a/libs/gui/Android.mk
+++ b/libs/gui/Android.mk
@@ -4,6 +4,7 @@
 LOCAL_SRC_FILES:= \
 	BitTube.cpp \
 	BufferQueue.cpp \
+	ConsumerBase.cpp \
 	DisplayEventReceiver.cpp \
 	IDisplayEventConnection.cpp \
 	ISensorEventConnection.cpp \