Plumbing for getting FenceTracker timestamps

Change-Id: I1ebee9e42e28658bd3a2b161fdaabb7da756d8f3
diff --git a/libs/gui/BufferQueue.cpp b/libs/gui/BufferQueue.cpp
index ccbb5a2..6de98f5 100644
--- a/libs/gui/BufferQueue.cpp
+++ b/libs/gui/BufferQueue.cpp
@@ -61,6 +61,15 @@
     }
 }
 
+bool BufferQueue::ProxyConsumerListener::getFrameTimestamps(
+        uint64_t frameNumber, FrameTimestamps* outTimestamps) const {
+    sp<ConsumerListener> listener(mConsumerListener.promote());
+    if (listener != NULL) {
+        return listener->getFrameTimestamps(frameNumber, outTimestamps);
+    }
+    return false;
+}
+
 void BufferQueue::createBufferQueue(sp<IGraphicBufferProducer>* outProducer,
         sp<IGraphicBufferConsumer>* outConsumer,
         const sp<IGraphicBufferAlloc>& allocator) {