Add Mojo IPC based input-device service.

ui/views/mus/window_manager_connection.cc

Index: ui/views/mus/window_manager_connection.cc
diff --git a/ui/views/mus/window_manager_connection.cc b/ui/views/mus/window_manager_connection.cc
index f17c0aa96379af0e4f4211482041711d4505c760..d1a926d2308a34c115c21739aa13d4063abe29c6 100644
--- a/ui/views/mus/window_manager_connection.cc
+++ b/ui/views/mus/window_manager_connection.cc
@@ -114,13 +114,8 @@ WindowManagerConnection::WindowManagerConnection(
   screen_.reset(new ScreenMus(this));
   screen_->Init(connector);
 
-  if (!ui::DeviceDataManager::HasInstance()) {
-    // TODO(sad): We should have a DeviceDataManager implementation that talks
-    // to a mojo service to learn about the input-devices on the system.
-    // http://crbug.com/601981
-    ui::DeviceDataManager::CreateInstance();
-    created_device_data_manager_ = true;
-  }
+  // Receives updates about input-devices from other another process.
+  input_device_client_.Connect(connector_);
 
   ViewsDelegate::GetInstance()->set_native_widget_factory(base::Bind(
       &WindowManagerConnection::CreateNativeWidgetMus,
@@ -132,8 +127,6 @@ WindowManagerConnection::~WindowManagerConnection() {
   // ~WindowTreeClient calls back to us (we're its delegate), destroy it while
   // we are still valid.
   client_.reset();
-  if (created_device_data_manager_)
-    ui::DeviceDataManager::DeleteInstance();
 
   if (ViewsDelegate::GetInstance()) {
     ViewsDelegate::GetInstance()->set_native_widget_factory(