diff --git a/include/input/Input.h b/include/input/Input.h
index f9fe6b9..bb5ca0e 100644
--- a/include/input/Input.h
+++ b/include/input/Input.h
@@ -266,6 +266,20 @@
 const char* motionClassificationToString(MotionClassification classification);
 
 /**
+ * Portion of FrameMetrics timeline of interest to input code.
+ */
+enum GraphicsTimeline : size_t {
+    /** Time when the app sent the buffer to SurfaceFlinger. */
+    GPU_COMPLETED_TIME = 0,
+
+    /** Time when the frame was presented on the display */
+    PRESENT_TIME = 1,
+
+    /** Total size of the 'GraphicsTimeline' array. Must always be last. */
+    SIZE = 2
+};
+
+/**
  * Generator of unique numbers used to identify input events.
  *
  * Layout of ID:
diff --git a/include/input/InputTransport.h b/include/input/InputTransport.h
index 3e5674e..898d1a9 100644
--- a/include/input/InputTransport.h
+++ b/include/input/InputTransport.h
@@ -71,6 +71,7 @@
         FOCUS,
         CAPTURE,
         DRAG,
+        TIMELINE,
     };
 
     struct Header {
@@ -195,6 +196,14 @@
 
             inline size_t size() const { return sizeof(Drag); }
         } drag;
+
+        struct Timeline {
+            int32_t eventId;
+            uint32_t empty;
+            std::array<nsecs_t, GraphicsTimeline::SIZE> graphicsTimeline;
+
+            inline size_t size() const { return sizeof(Timeline); }
+        } timeline;
     } __attribute__((aligned(8))) body;
 
     bool isValid(size_t actualSize) const;
@@ -381,10 +390,25 @@
         nsecs_t consumeTime;
     };
 
-    /* Receives the finished signal from the consumer in reply to the original dispatch signal.
-     * If a signal was received, returns a Finished object.
+    struct Timeline {
+        int32_t inputEventId;
+        std::array<nsecs_t, GraphicsTimeline::SIZE> graphicsTimeline;
+    };
+
+    typedef std::variant<Finished, Timeline> ConsumerResponse;
+    /* Receive a signal from the consumer in reply to the original dispatch signal.
+     * If a signal was received, returns a Finished or a Timeline object.
+     * The InputConsumer should return a Finished object for every InputMessage that it is sent
+     * to confirm that it has been processed and that the InputConsumer is responsive.
+     * If several InputMessages are sent to InputConsumer, it's possible to receive Finished
+     * events out of order for those messages.
      *
-     * The returned sequence number is never 0 unless the operation failed.
+     * The Timeline object is returned whenever the receiving end has processed a graphical frame
+     * and is returning the timeline of the frame. Not all input events will cause a Timeline
+     * object to be returned, and there is not guarantee about when it will arrive.
+     *
+     * If an object of Finished is returned, the returned sequence number is never 0 unless the
+     * operation failed.
      *
      * Returned error codes:
      *         OK on success.
@@ -392,7 +416,7 @@
      *         DEAD_OBJECT if the channel's peer has been closed.
      *         Other errors probably indicate that the channel is broken.
      */
-    android::base::Result<Finished> receiveFinishedSignal();
+    android::base::Result<ConsumerResponse> receiveConsumerResponse();
 
 private:
     std::shared_ptr<InputChannel> mChannel;
@@ -448,6 +472,9 @@
      */
     status_t sendFinishedSignal(uint32_t seq, bool handled);
 
+    status_t sendTimeline(int32_t inputEventId,
+                          std::array<nsecs_t, GraphicsTimeline::SIZE> timeline);
+
     /* Returns true if there is a deferred event waiting.
      *
      * Should be called after calling consume() to determine whether the consumer