Change CaptureSynchronizer and PointerWatcherEventRouter to support multiple CaptureClients.

ui/aura/mus/window_tree_client.cc

 // Copyright 2014 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/mus/window_tree_client.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <utility>
@@ skipping 449 matching lines @@
     tree_ptr_->GetWindowManagerClient(MakeRequest(
         &window_manager_internal_client_, tree_ptr_.associated_group()));
   }
 }
 
 void WindowTreeClient::WindowTreeConnectionEstablished(
     ui::mojom::WindowTree* window_tree) {
   tree_ = window_tree;
 
   drag_drop_controller_ = base::MakeUnique<DragDropControllerMus>(this, tree_);
-  capture_synchronizer_ =
-      base::MakeUnique<CaptureSynchronizer>(this, tree_, GetCaptureClient());
+  capture_synchronizer_ = base::MakeUnique<CaptureSynchronizer>(this, tree_);
   focus_synchronizer_ = base::MakeUnique<FocusSynchronizer>(this, tree_);
 }
 
 void WindowTreeClient::OnConnectionLost() {
   delegate_->OnLostConnection(this);
 }
 
 bool WindowTreeClient::HandleInternalPropertyChanged(WindowMus* window,
                                                      const void* key) {
   if (key != client::kModalKey)
@@ skipping 1340 matching lines @@
   return ScheduleInFlightChange(base::MakeUnique<InFlightCaptureChange>(
       this, capture_synchronizer_.get(), window));
 }
 
 uint32_t WindowTreeClient::CreateChangeIdForFocus(WindowMus* window) {
   return ScheduleInFlightChange(base::MakeUnique<InFlightFocusChange>(
       this, focus_synchronizer_.get(), window));
 }
 
 }  // namespace aura