Improve SF dumpsys output wrt HWC

Change-Id: Ibdb7930fa3b521bfd3f44750ed98cfd75f9a01fe
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 77c1a4b..8758a80 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -25,12 +25,14 @@
 #include <hardware/hwcomposer.h>
 
 #include <utils/StrongPointer.h>
+#include <utils/Vector.h>
 
 namespace android {
 // ---------------------------------------------------------------------------
 
 class String8;
 class SurfaceFlinger;
+class LayerBase;
 
 class HWComposer
 {
@@ -63,7 +65,8 @@
     hwc_layer_t* getLayers() const;
 
     // for debugging
-    void dump(String8& out, char* scratch, size_t SIZE) const;
+    void dump(String8& out, char* scratch, size_t SIZE,
+            const Vector< sp<LayerBase> >& visibleLayersSortedByZ) const;
 
 private:
     struct cb_context {