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

services/ui/public/cpp/context_provider.h

Index: services/ui/public/cpp/context_provider.h
diff --git a/services/ui/public/cpp/context_provider.h b/services/ui/public/cpp/context_provider.h
index f17131ed8958252c82a83bb177783e6fe35f57fc..586fdef9e00391620c48a158f8df6fef0d40a2ff 100644
--- a/services/ui/public/cpp/context_provider.h
+++ b/services/ui/public/cpp/context_provider.h
@@ -12,6 +12,7 @@
 #include "base/macros.h"
 #include "cc/output/context_provider.h"
 #include "mojo/public/cpp/system/core.h"
+#include "services/ui/public/cpp/ui_export.h"
 #include "services/ui/public/interfaces/command_buffer.mojom.h"
 
 namespace shell {
@@ -22,7 +23,8 @@ namespace ui {
 
 class GLES2Context;
 
-class ContextProvider : public cc::ContextProvider {
+class UI_EXPORT ContextProvider
+    : NON_EXPORTED_BASE(public cc::ContextProvider) {
  public:
   ContextProvider();