services/ui: Create a proper component for the client-lib.

services/ui/public/cpp/input_event_handler.h

Index: services/ui/public/cpp/input_event_handler.h
diff --git a/services/ui/public/cpp/input_event_handler.h b/services/ui/public/cpp/input_event_handler.h
index 837ee10246ae9ad12b4354f5f185e74bbafe6498..28a163df825a9d74acdee9d5951b9986511c9d91 100644
--- a/services/ui/public/cpp/input_event_handler.h
+++ b/services/ui/public/cpp/input_event_handler.h
@@ -8,6 +8,7 @@
 #include <memory>
 
 #include "base/callback_forward.h"
+#include "services/ui/public/cpp/ui_export.h"
 
 namespace ui {
 class Event;
@@ -22,7 +23,7 @@ enum class EventResult;
 }
 
 // Responsible for processing input events for ui::Window.
-class InputEventHandler {
+class UI_EXPORT InputEventHandler {
  public:
   // The event handler can asynchronously ack the event by taking ownership of
   // the |ack_callback|. The callback takes an EventResult indicating if the