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

ui/ozone/platform/caca/ozone_platform_caca.h

Index: ui/ozone/platform/caca/ozone_platform_caca.h
diff --git a/ui/ozone/platform/caca/ozone_platform_caca.h b/ui/ozone/platform/caca/ozone_platform_caca.h
index bf1f73520882334ad401617e4cda8956e4cf9f2f..8f08cf35616063bc472f2c625b959cc5f45dde8f 100644
--- a/ui/ozone/platform/caca/ozone_platform_caca.h
+++ b/ui/ozone/platform/caca/ozone_platform_caca.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* CreateOzonePlatformCaca();
 
+// Constructor hook for use in constructor_list.cc
+NativePixmapClient* CreateNativePixmapClientCaca();
+
 }  // namespace ui
 
 #endif  // UI_OZONE_PLATFORM_CACA_OZONE_PLATFORM_CACA_H_