Make embedded hardware layers work.
Bug #3369474

Change-Id: Ib6d7fb44eedda9dc2933b5e1b176f307968af91d
diff --git a/libs/hwui/OpenGLRenderer.h b/libs/hwui/OpenGLRenderer.h
index 272c5c2..4150ddc 100644
--- a/libs/hwui/OpenGLRenderer.h
+++ b/libs/hwui/OpenGLRenderer.h
@@ -145,14 +145,27 @@
         return mSnapshot;
     }
 
+    /**
+     * Returns the region of the current layer.
+     */
     virtual Region* getRegion() {
         return mSnapshot->region;
     }
 
+    /**
+     * Indicates whether rendering is currently targeted at a layer.
+     */
     virtual bool hasLayer() {
         return (mSnapshot->flags & Snapshot::kFlagFboTarget) && mSnapshot->region;
     }
 
+    /**
+     * Returns the name of the FBO this renderer is rendering into.
+     */
+    virtual GLint getTargetFbo() {
+        return 0;
+    }
+
 private:
     /**
      * Saves the current state of the renderer as a new snapshot.