BufferQueue: Add StreamSplitter

Adds a StreamSplitter class, that takes one IGraphicBufferConsumer
interface and multiple IGraphicBufferProducer interfaces and
implements a one-to-many broadcast of GraphicBuffers (while managing
fences correctly).

Change-Id: I38ecdf3e311ac521bc781c30dde0cc382a4376a3
diff --git a/libs/gui/Android.mk b/libs/gui/Android.mk
index 04a8a8d..ca94aa3 100644
--- a/libs/gui/Android.mk
+++ b/libs/gui/Android.mk
@@ -30,6 +30,7 @@
 	Sensor.cpp \
 	SensorEventQueue.cpp \
 	SensorManager.cpp \
+	StreamSplitter.cpp \
 	Surface.cpp \
 	SurfaceControl.cpp \
 	SurfaceComposerClient.cpp \