Allowing WhispernetClient to be used during initialization

components/copresence/handlers/directive_handler.h

Index: components/copresence/handlers/directive_handler.h
diff --git a/components/copresence/handlers/directive_handler.h b/components/copresence/handlers/directive_handler.h
index 24e17894ac032f64a225c8468132da603089e826..5c3f6ea7c0535973a676eef0ca320e26c9f92854 100644
--- a/components/copresence/handlers/directive_handler.h
+++ b/components/copresence/handlers/directive_handler.h
@@ -26,6 +26,7 @@ class DirectiveHandler {
   // |whispernet_client| is owned by the caller and must outlive the
   // DirectiveHandler.
   // |tokens_cb| is called for all audio tokens found in recorded audio.
+  // TODO(ckehoe): This is no longer needed. Merge into the constructor.
   virtual void Start(WhispernetClient* whispernet_client,
                      const TokensCallback& tokens_cb) = 0;