Use a shared state for egl::Image.

This allows us to stop duplicating some information in the impl.

BUG=angleproject:1635

Change-Id: If8f7d2418571c3254729f48c463814ec18ed2644
Reviewed-on: https://chromium-review.googlesource.com/469153
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
diff --git a/src/libANGLE/renderer/null/DisplayNULL.cpp b/src/libANGLE/renderer/null/DisplayNULL.cpp
index 1caa7c8..61b3a8a 100644
--- a/src/libANGLE/renderer/null/DisplayNULL.cpp
+++ b/src/libANGLE/renderer/null/DisplayNULL.cpp
@@ -164,11 +164,11 @@
     return new SurfaceNULL(state);
 }
 
-ImageImpl *DisplayNULL::createImage(EGLenum target,
-                                    egl::ImageSibling *buffer,
+ImageImpl *DisplayNULL::createImage(const egl::ImageState &state,
+                                    EGLenum target,
                                     const egl::AttributeMap &attribs)
 {
-    return new ImageNULL();
+    return new ImageNULL(state);
 }
 
 ContextImpl *DisplayNULL::createContext(const gl::ContextState &state)