Revert: Change CaptureSynchronizer and PointerWatcherEventRouter to support multiple CaptureClients

ui/views/mus/mus_client.h

Index: ui/views/mus/mus_client.h
diff --git a/ui/views/mus/mus_client.h b/ui/views/mus/mus_client.h
index 568f7164e28fb91e3c27da198eded209615a2219..cccc44b082fcfeb4efd46b6119b25f550e63f1c7 100644
--- a/ui/views/mus/mus_client.h
+++ b/ui/views/mus/mus_client.h
@@ -12,7 +12,6 @@
 #include <vector>
 
 #include "base/macros.h"
-#include "ui/aura/client/capture_client.h"
 #include "ui/aura/mus/window_tree_client_delegate.h"
 #include "ui/base/dragdrop/os_exchange_data_provider_factory.h"
 #include "ui/views/mus/mus_export.h"
@@ -102,14 +101,6 @@
   NativeWidget* CreateNativeWidget(const Widget::InitParams& init_params,
                                    internal::NativeWidgetDelegate* delegate);
 
-  // Called when the capture client has been set for a window to notify
-  // PointerWatcherEventRouter and CaptureSynchronizer.
-  void OnCaptureClientSet(aura::client::CaptureClient* capture_client);
-
-  // Called when the capture client will be unset for a window to notify
-  // PointerWatcherEventRouter and CaptureSynchronizer.
-  void OnCaptureClientUnset(aura::client::CaptureClient* capture_client);
-
   void AddObserver(MusClientObserver* observer);
   void RemoveObserver(MusClientObserver* observer);