Use LayoutObjectFactory for HTMLImageElement.

Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_layout_ng
Change-Id: I4aeecfada142ad85b575703a4a9ed66c4228714b
Reviewed-on: https://chromium-review.googlesource.com/1101326
Commit-Queue: Morten Stenshorne <mstensho@chromium.org>
Commit-Queue: Emil A Eklund <eae@chromium.org>
Reviewed-by: Emil A Eklund <eae@chromium.org>
Reviewed-by: Christian Biesinger <cbiesinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567397}

third_party/blink/renderer/core/html/html_image_element.cc

@@ -49,6 +49,7 @@
 #include "third_party/blink/renderer/core/layout/adjust_for_absolute_zoom.h"
 #include "third_party/blink/renderer/core/layout/layout_block_flow.h"
 #include "third_party/blink/renderer/core/layout/layout_image.h"
+#include "third_party/blink/renderer/core/layout/layout_object_factory.h"
 #include "third_party/blink/renderer/core/layout/ng/layout_ng_block_flow.h"
 #include "third_party/blink/renderer/core/loader/resource/image_resource_content.h"
 #include "third_party/blink/renderer/core/media_type_names.h"
@@ -356,10 +357,7 @@ LayoutObject* HTMLImageElement::CreateLayoutObject(const ComputedStyle& style) {
 
   switch (layout_disposition_) {
     case LayoutDisposition::kFallbackContent:
-      if (!RuntimeEnabledFeatures::LayoutNGEnabled() ||
-          style.ForceLegacyLayout())
-        return new LayoutBlockFlow(this);
-      return new LayoutNGBlockFlow(this);
+      return LayoutObjectFactory::CreateBlockFlow(*this, style);
     case LayoutDisposition::kPrimaryContent: {
       LayoutImage* image = new LayoutImage(this);
       image->SetImageResource(LayoutImageResource::Create());