[cc] Pass on BeginFrameAcks from CompositorEBFS through RWHVAura, DFH.

cc/ipc/begin_frame_args_struct_traits.h

Index: cc/ipc/begin_frame_args_struct_traits.h
diff --git a/cc/ipc/begin_frame_args_struct_traits.h b/cc/ipc/begin_frame_args_struct_traits.h
index 4d813395c282743b2c57f38985b3572113db3993..35a9181d78d4eebe6c783b0e5f88625e4a2b4bc5 100644
--- a/cc/ipc/begin_frame_args_struct_traits.h
+++ b/cc/ipc/begin_frame_args_struct_traits.h
@@ -41,19 +41,26 @@ struct StructTraits<cc::mojom::BeginFrameArgsDataView, cc::BeginFrameArgs> {
   }
 
   static bool Read(cc::mojom::BeginFrameArgsDataView data,
-                   cc::BeginFrameArgs* out) {
-    if (!data.ReadFrameTime(&out->frame_time) ||
-        !data.ReadDeadline(&out->deadline) ||
-        !data.ReadInterval(&out->interval)) {
-      return false;
-    }
-    out->source_id = data.source_id();
-    out->sequence_number = data.sequence_number();
-    out->type =
-        static_cast<cc::BeginFrameArgs::BeginFrameArgsType>(data.type());
-    out->on_critical_path = data.on_critical_path();
-    return true;
+                   cc::BeginFrameArgs* out);
+};
+
+template <>
+struct StructTraits<cc::mojom::BeginFrameAckDataView, cc::BeginFrameAck> {
+  static uint64_t sequence_number(const cc::BeginFrameAck& ack) {
+    return ack.sequence_number;
+  }
+
+  static uint64_t latest_confirmed_sequence_number(
+      const cc::BeginFrameAck& ack) {
+    return ack.latest_confirmed_sequence_number;
+  }
+
+  static uint32_t source_id(const cc::BeginFrameAck& ack) {
+    return ack.source_id;
   }
+
+  static bool Read(cc::mojom::BeginFrameAckDataView data,
+                   cc::BeginFrameAck* out);
 };
 
 }  // namespace mojo