Change GL references to GPU for getFrameTimestamps.

Test: Rename only.

Change-Id: Idaf7ab38f78f58aa8387823f47dac084e21eb1f0
diff --git a/include/gui/FrameTimestamps.h b/include/gui/FrameTimestamps.h
index 9e1ae94..174c5ea 100644
--- a/include/gui/FrameTimestamps.h
+++ b/include/gui/FrameTimestamps.h
@@ -41,7 +41,7 @@
     ACQUIRE,
     FIRST_REFRESH_START,
     LAST_REFRESH_START,
-    GL_COMPOSITION_DONE,
+    GPU_COMPOSITION_DONE,
     DISPLAY_PRESENT,
     DISPLAY_RETIRE,
     DEQUEUE_READY,