update SF binder protocol to support setting display attributes

no change of functionality -- the old behavior is implemented
on top of this new protocol.
this new protocol will allow, eventually, to pass informations
about displays and layer stacks.

Change-Id: Ic6c2295e61ec8ecbc8ce01ab7664e35d928202fc
diff --git a/include/private/gui/LayerState.h b/include/private/gui/LayerState.h
index 239dd87..97891e4 100644
--- a/include/private/gui/LayerState.h
+++ b/include/private/gui/LayerState.h
@@ -77,6 +77,17 @@
     status_t    read(const Parcel& input);
 };
 
+struct DisplayState {
+    int32_t             displayId;
+    sp<ISurfaceTexture> surface;
+    uint32_t            layerStack;
+    uint32_t            orientation;
+    Rect                viewport;
+    Rect                frame;
+    status_t    write(Parcel& output) const;
+    status_t    read(const Parcel& input);
+};
+
 }; // namespace android
 
 #endif // ANDROID_SF_LAYER_STATE_H