[FragmentItem] Fix use-of-uninitialized-value

This patch fixes an use-of-uninitialized-value accidentally
introduced in r746511 <crrev.com/c/2079775>.

|is_hanging_| is initialized and should be used only for
|NGPhysicalLineBoxFragment|. The CL passes |is_hanging_| as
an argument for this purpose, but the function mistakenly
uses it in the super class, instead of using the one passed
by the argument.

Bug: 982194
Change-Id: I3b33595fa0305f92408914b9ac77d15fbccb9d27
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2086456Reviewed-by: Kent Tamura <tkent@chromium.org>
Commit-Queue: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#746664}

third_party/blink/renderer/core/layout/ng/ng_physical_container_fragment.cc

@@ -133,7 +133,7 @@ void NGPhysicalContainerFragment::AddScrollableOverflowForInlineChild(
     DCHECK(item);
     if (item->IsText()) {
       PhysicalRect child_scroll_overflow = item->RectInContainerBlock();
-      if (UNLIKELY(has_hanging_)) {
+      if (UNLIKELY(has_hanging)) {
         AdjustScrollableOverflowForHanging(line.RectInContainerBlock(),
                                            container_writing_mode,
                                            &child_scroll_overflow);