Remove unused CompositorFrameSink capability

cc/output/compositor_frame_sink.h

Index: cc/output/compositor_frame_sink.h
diff --git a/cc/output/compositor_frame_sink.h b/cc/output/compositor_frame_sink.h
index a69412924af0290e23f2884e4d201f6c5c3668aa..d2694afcffe13d1071f7cae3a59132103ac1bb5e 100644
--- a/cc/output/compositor_frame_sink.h
+++ b/cc/output/compositor_frame_sink.h
@@ -51,10 +51,6 @@ class CC_EXPORT CompositorFrameSink
   struct Capabilities {
     Capabilities() = default;
 
-    // TODO(enne): Remove this since everything uses begin frames now, but it
-    // causes some racey unit tests to fail.
-    bool adjust_deadline_for_parent = true;
-
     // Whether ForceReclaimResources can be called to reclaim all resources
     // from the CompositorFrameSink.
     bool can_force_reclaim_resources = false;