ozone: Introduce ClientPixmap and ClientPixmapFactory for non-GPU processes.

ui/ozone/platform/cast/ozone_platform_cast.h

Index: ui/ozone/platform/cast/ozone_platform_cast.h
diff --git a/ui/ozone/platform/cast/ozone_platform_cast.h b/ui/ozone/platform/cast/ozone_platform_cast.h
index 7698c1acd6ae1792fb9ea33ea3a420529bbeadec..154abad5ce10c95edfc03762120ed1b45245ad34 100644
--- a/ui/ozone/platform/cast/ozone_platform_cast.h
+++ b/ui/ozone/platform/cast/ozone_platform_cast.h
@@ -7,11 +7,15 @@
 
 namespace ui {
 
+class OzoneClient;
 class OzonePlatform;
 
 // Constructor hook for use in ozone_platform_list.cc
 OzonePlatform* CreateOzonePlatformCast();
 
+// Constructor hook for use in constructor_client_list.cc
+OzoneClient* CreateOzoneClientCast();
+
 }  // namespace ui
 
 #endif  // UI_OZONE_PLATFORM_CAST_OZONE_PLATFORM_CAST_H