Make the first app to request input win

services/ui/input_manager/input_associate.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "services/ui/input_manager/input_associate.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "mojo/public/cpp/bindings/interface_request.h"
 
@@ skipping 36 matching lines @@
     input_dispatchers_.AddBinding(
         new InputDispatcherImpl(this, view_tree_token.Pass()),
         mojo::MakeRequest<mojo::ui::InputDispatcher>(client_handle.Pass()));
   }
 }
 
 void InputAssociate::SetListener(mojo::ui::ViewToken* view_token,
                                  mojo::ui::InputListenerPtr listener) {
   // TODO(jeffbrown): This simple hack just hooks up the first listener
   // ever seen.
-  listener_ = listener.Pass();
+  if (!listener_)
+    listener_ = listener.Pass();
 }
 
 void InputAssociate::DispatchEvent(mojo::ui::ViewTreeToken* view_tree_token,
                                    mojo::EventPtr event) {
   if (listener_)
     listener_->OnEvent(
         event.Pass(),
         base::Bind(&InputAssociate::OnEventFinished, base::Unretained(this)));
 }
 
@@ skipping 24 matching lines @@
   DCHECK(view_tree_token_);
 }
 
 InputAssociate::InputDispatcherImpl::~InputDispatcherImpl() {}
 
 void InputAssociate::InputDispatcherImpl::DispatchEvent(mojo::EventPtr event) {
   associate_->DispatchEvent(view_tree_token_.get(), event.Pass());
 }
 
 }  // namespace input_manager