Pass sp<Fence>s around instead of file descriptors

Change-Id: Iac70584a2207940730e8f803a543e4e9a4000c47
diff --git a/services/surfaceflinger/DisplayHardware/FramebufferSurface.h b/services/surfaceflinger/DisplayHardware/FramebufferSurface.h
index 1402740..164f81f 100644
--- a/services/surfaceflinger/DisplayHardware/FramebufferSurface.h
+++ b/services/surfaceflinger/DisplayHardware/FramebufferSurface.h
@@ -43,7 +43,7 @@
 
     virtual status_t compositionComplete();
     virtual status_t advanceFrame();
-    virtual void onFrameCommitted(int fenceFd);
+    virtual void onFrameCommitted(const sp<Fence>& fence);
 
     // Implementation of DisplaySurface::dump(). Note that ConsumerBase also
     // has a non-virtual dump() with the same signature.