libgui: Hook up onFrameReplaced

This completes the plumbing from ConsumerListener::onFrameReplaced into
SurfaceFlinger (and other consumers that may care).

Change-Id: I376e78ace95d6748e8662e6b4d47c0dfa697a300
diff --git a/services/surfaceflinger/Layer.h b/services/surfaceflinger/Layer.h
index 46c17e5..0b4c640 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -339,9 +339,9 @@
 
 private:
     // Interface implementation for SurfaceFlingerConsumer::ContentsChangedListener
-    virtual void onFrameAvailable(const BufferItem& item);
-    virtual void onFrameReplaced(const BufferItem& item);
-    virtual void onSidebandStreamChanged();
+    virtual void onFrameAvailable(const BufferItem& item) override;
+    virtual void onFrameReplaced(const BufferItem& item) override;
+    virtual void onSidebandStreamChanged() override;
 
     void commitTransaction();