gralloc: add dump hooks to gralloc/hwcomposer

Change-Id: I27bf46103b4d1d547c42a6de4f3270a6dfd7b7ec
diff --git a/include/hardware/hwcomposer.h b/include/hardware/hwcomposer.h
index c72d466..321dfc1 100644
--- a/include/hardware/hwcomposer.h
+++ b/include/hardware/hwcomposer.h
@@ -278,8 +278,14 @@
                 hwc_display_t dpy,
                 hwc_surface_t sur,
                 hwc_layer_list_t* list);
+    /*
+     * This hook is OPTIONAL.
+     *
+     * If non NULL it will be caused by SurfaceFlinger on dumpsys
+     */
+    void (*dump)(struct hwc_composer_device* dev, char *buff, int buff_len);
 
-    void* reserved_proc[8];
+    void* reserved_proc[7];
 
 } hwc_composer_device_t;