SurfaceFlinger: Expose construction of container layers.

WindowManager will imminently use them as Buffer-less Surfaces for catching
input. They can also be used for the existing hierarchy layers that the WM
adds to solely act as containers.

Bug: 111440400
Test: None
Change-Id: Ic7d9234d7fd8be74b77dfbc3daa6ca0e52f25768
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 3dbceae..60abb05 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -548,6 +548,10 @@
             uint32_t w, uint32_t h, uint32_t flags, sp<IBinder>* outHandle,
             sp<Layer>* outLayer);
 
+    status_t createContainerLayer(const sp<Client>& client, const String8& name,
+            uint32_t w, uint32_t h, uint32_t flags, sp<IBinder>* outHandle,
+            sp<Layer>* outLayer);
+
     String8 getUniqueLayerName(const String8& name);
 
     // called in response to the window-manager calling