surfaceflinger: refactor FrambufferSurface

This change refactors the FramebufferSurface class to inherit from the new
ConsumerBase class.

Bug: 6620200
Change-Id: I46ec942ddb019658e3c5e79465548b171b2261f2
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index b9c9337..607cbae 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -42,6 +42,7 @@
 
 class GraphicBuffer;
 class LayerBase;
+class Region;
 class String8;
 class SurfaceFlinger;