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/tests/Android.mk b/libs/gui/tests/Android.mk
index 2eeb5c7..e460290 100644
--- a/libs/gui/tests/Android.mk
+++ b/libs/gui/tests/Android.mk
@@ -14,6 +14,7 @@
     IGraphicBufferProducer_test.cpp \
     MultiTextureConsumer_test.cpp \
     SRGB_test.cpp \
+    StreamSplitter_test.cpp \
     SurfaceTextureClient_test.cpp \
     SurfaceTextureFBO_test.cpp \
     SurfaceTextureGLThreadToGL_test.cpp \