diff --git a/include/gui/ConsumerBase.h b/include/gui/ConsumerBase.h
index 6250d8f..1d51bc9 100644
--- a/include/gui/ConsumerBase.h
+++ b/include/gui/ConsumerBase.h
@@ -160,17 +160,23 @@
     // Derived classes should override this method to perform any cleanup that
     // must take place when a buffer is released back to the BufferQueue.  If
     // it is overridden the derived class's implementation must call
-    // ConsumerBase::releaseBufferLocked.
-    virtual status_t releaseBufferLocked(int buf, EGLDisplay display,
-           EGLSyncKHR eglFence);
+    // ConsumerBase::releaseBufferLocked.e
+    virtual status_t releaseBufferLocked(int slot,
+            const sp<GraphicBuffer> graphicBuffer,
+            EGLDisplay display, EGLSyncKHR eglFence);
+
+    // returns true iff the slot still has the graphicBuffer in it.
+    bool stillTracking(int slot, const sp<GraphicBuffer> graphicBuffer);
 
     // addReleaseFence* adds the sync points associated with a fence to the set
     // of sync points that must be reached before the buffer in the given slot
     // may be used after the slot has been released.  This should be called by
     // derived classes each time some asynchronous work is kicked off that
     // references the buffer.
-    status_t addReleaseFence(int slot, const sp<Fence>& fence);
-    status_t addReleaseFenceLocked(int slot, const sp<Fence>& fence);
+    status_t addReleaseFence(int slot,
+            const sp<GraphicBuffer> graphicBuffer, const sp<Fence>& fence);
+    status_t addReleaseFenceLocked(int slot,
+            const sp<GraphicBuffer> graphicBuffer, const sp<Fence>& fence);
 
     // Slot contains the information and object references that
     // ConsumerBase maintains about a BufferQueue buffer slot.
@@ -184,6 +190,9 @@
         // overwritten. The buffer can be dequeued before the fence signals;
         // the producer is responsible for delaying writes until it signals.
         sp<Fence> mFence;
+
+        // the frame number of the last acquired frame for this slot
+        uint64_t mFrameNumber;
     };
 
     // mSlots stores the buffers that have been allocated by the BufferQueue