aura-mus: wire up drag and drop.

ui/views/mus/mus_client.cc

Index: ui/views/mus/mus_client.cc
diff --git a/ui/views/mus/mus_client.cc b/ui/views/mus/mus_client.cc
index cc3624b70d4f9396114a83f54db72ad679230cd0..d03fe330023562bae0eb1a4c7501bae58b50e42f 100644
--- a/ui/views/mus/mus_client.cc
+++ b/ui/views/mus/mus_client.cc
@@ -18,7 +18,6 @@
 #include "ui/aura/env.h"
 #include "ui/aura/mus/capture_synchronizer.h"
 #include "ui/aura/mus/mus_context_factory.h"
-#include "ui/aura/mus/os_exchange_data_provider_mus.h"
 #include "ui/aura/mus/property_converter.h"
 #include "ui/aura/mus/window_tree_client.h"
 #include "ui/aura/mus/window_tree_host_mus.h"
@@ -112,8 +111,6 @@ MusClient::MusClient(service_manager::Connector* connector,
   clipboard->Init(connector);
   ui::Clipboard::SetClipboardForCurrentThread(std::move(clipboard));
 
-  ui::OSExchangeDataProviderFactory::SetFactory(this);
-
   ViewsDelegate::GetInstance()->set_native_widget_factory(
       base::Bind(&MusClient::CreateNativeWidget, base::Unretained(this)));
 }
@@ -297,8 +294,4 @@ aura::Window* MusClient::GetWindowAtScreenPoint(const gfx::Point& point) {
   return nullptr;
 }
 
-std::unique_ptr<OSExchangeData::Provider> MusClient::BuildProvider() {
-  return base::MakeUnique<aura::OSExchangeDataProviderMus>();
-}
-
 }  // namespace views