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

services/ui/public/cpp/output_surface.h

Index: services/ui/public/cpp/output_surface.h
diff --git a/services/ui/public/cpp/output_surface.h b/services/ui/public/cpp/output_surface.h
index 384f4ecc9922f7eb754c1c338685c97bbc43326c..6f5d56d83f4a7c37856be20e10395b36b59f5014 100644
--- a/services/ui/public/cpp/output_surface.h
+++ b/services/ui/public/cpp/output_surface.h
@@ -9,12 +9,14 @@
 #include "cc/output/output_surface.h"
 #include "cc/surfaces/surface_id.h"
 #include "mojo/public/cpp/bindings/binding.h"
+#include "services/ui/public/cpp/ui_export.h"
 #include "services/ui/public/cpp/window_surface.h"
 #include "services/ui/public/cpp/window_surface_client.h"
 
 namespace ui {
 
-class OutputSurface : public cc::OutputSurface, public WindowSurfaceClient {
+class UI_EXPORT OutputSurface : public cc::OutputSurface,
+                                public WindowSurfaceClient {
  public:
   OutputSurface(const scoped_refptr<cc::ContextProvider>& context_provider,
                 std::unique_ptr<WindowSurface> surface);