Change CaptureSynchronizer and PointerWatcherEventRouter to support multiple CaptureClients.

ui/aura/test/aura_test_helper.cc

 // Copyright (c) 2012 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 "ui/aura/test/aura_test_helper.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "ui/aura/client/default_capture_client.h"
 #include "ui/aura/client/focus_client.h"
 #include "ui/aura/env.h"
 #include "ui/aura/input_state_lookup.h"
+#include "ui/aura/mus/capture_synchronizer.h"
 #include "ui/aura/mus/window_port_mus.h"
 #include "ui/aura/mus/window_tree_client.h"
 #include "ui/aura/test/env_test_helper.h"
 #include "ui/aura/test/event_generator_delegate_aura.h"
 #include "ui/aura/test/mus/test_window_tree.h"
 #include "ui/aura/test/mus/test_window_tree_client_setup.h"
 #include "ui/aura/test/test_focus_client.h"
 #include "ui/aura/test/test_screen.h"
 #include "ui/aura/test/test_window_parenting_client.h"
 #include "ui/aura/window.h"
@@ skipping 164 matching lines @@
 
 client::CaptureClient* AuraTestHelper::capture_client() {
   return capture_client_.get();
 }
 
 void AuraTestHelper::InitWindowTreeClient() {
   window_tree_client_setup_ = base::MakeUnique<TestWindowTreeClientSetup>();
   window_tree_client_setup_->InitForWindowManager(window_tree_delegate_,
                                                   window_manager_delegate_);
   window_tree_client_ = window_tree_client_setup_->window_tree_client();
+  window_tree_client_->capture_synchronizer()->AttachToCaptureClient(
+      capture_client_.get());
 }
 
 }  // namespace test
 }  // namespace aura