veyron2/ipc,veyron/runtimes/google/ipc: Make the blessings used to authenticate
the server accessible to the client in ipc.Call.

Change-Id: I50e5aede707ad6375cea245429ee2c056c9504c5
diff --git a/runtimes/google/ipc/client.go b/runtimes/google/ipc/client.go
index 358d78b..51f7706 100644
--- a/runtimes/google/ipc/client.go
+++ b/runtimes/google/ipc/client.go
@@ -536,3 +536,8 @@
 	vtrace.FromContext(fc.ctx).Annotate("Cancelled")
 	fc.flow.Cancel()
 }
+
+func (fc *flowClient) RemoteBlessings() ([]string, security.Blessings) {
+	// TODO(ashankar): Fill in the second result once the switch to the new API is complete.
+	return fc.flow.RemoteID().Names(), nil
+}