Add sideband streams to BufferQueue and related classes

Sideband streams are essentially a device-specific buffer queue that
bypasses the BufferQueue system. They can be used for situations with
hard real-time requirements like high-quality TV and video playback
with A/V sync. A handle to the stream is provided by the source HAL,
and attached to a BufferQueue. The sink HAL can read buffers via the
stream handle rather than acquiring individual buffers from the
BufferQueue.

Change-Id: Ib3f262eddfc520f4bbe3d9b91753ed7dd09d3a9b
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 9f96113..9218bf6 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -45,9 +45,10 @@
 namespace android {
 // ---------------------------------------------------------------------------
 
-class GraphicBuffer;
 class Fence;
 class FloatRect;
+class GraphicBuffer;
+class NativeHandle;
 class Region;
 class String8;
 class SurfaceFlinger;
@@ -164,6 +165,7 @@
         virtual void setFrame(const Rect& frame) = 0;
         virtual void setCrop(const FloatRect& crop) = 0;
         virtual void setVisibleRegionScreen(const Region& reg) = 0;
+        virtual void setSidebandStream(const sp<NativeHandle>& stream) = 0;
         virtual void setBuffer(const sp<GraphicBuffer>& buffer) = 0;
         virtual void setAcquireFenceFd(int fenceFd) = 0;
         virtual void setPlaneAlpha(uint8_t alpha) = 0;