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..a57f6be752e1488ea706c6c4ada510e026064fa8 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 NativePixmapClient;
 class OzonePlatform;
 
-// Constructor hook for use in ozone_platform_list.cc
+// Constructor hook for use in constructor_list.cc
 OzonePlatform* CreateOzonePlatformCast();
 
+// Constructor hook for use in constructor_list.cc
+NativePixmapClient* CreateNativePixmapClientCast();
+
 }  // namespace ui
 
 #endif  // UI_OZONE_PLATFORM_CAST_OZONE_PLATFORM_CAST_H