[cleanup] Remove dead member from LayoutFrameset

There should be no behaviour change.

Change-Id: I39333abd5ef6c5650c2bc7b333e08eb36c31ad8b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1946424
Commit-Queue: Ian Kilpatrick <ikilpatrick@chromium.org>
Commit-Queue: Christian Biesinger <cbiesinger@chromium.org>
Auto-Submit: Ian Kilpatrick <ikilpatrick@chromium.org>
Reviewed-by: Christian Biesinger <cbiesinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#721251}

third_party/blink/renderer/core/layout/layout_frame_set.cc

@@ -49,7 +49,7 @@ static int AdjustSizeToRemainingSize(int current,
 }
 
 LayoutFrameSet::LayoutFrameSet(HTMLFrameSetElement* frame_set)
-    : LayoutBox(frame_set), is_resizing_(false), is_child_resizing_(false) {
+    : LayoutBox(frame_set), is_resizing_(false) {
   SetInline(false);
 }
 
@@ -517,11 +517,6 @@ bool LayoutFrameSet::UserResize(const MouseEvent& evt) {
 
 void LayoutFrameSet::SetIsResizing(bool is_resizing) {
   is_resizing_ = is_resizing;
-  for (LayoutObject* ancestor = Parent(); ancestor;
-       ancestor = ancestor->Parent()) {
-    if (ancestor->IsFrameSet())
-      ToLayoutFrameSet(ancestor)->is_child_resizing_ = is_resizing;
-  }
   if (LocalFrame* frame = GetFrame()) {
     frame->GetEventHandler().SetResizingFrameSet(is_resizing ? FrameSet()
                                                              : nullptr);

third_party/blink/renderer/core/layout/layout_frame_set.h

@@ -159,7 +159,6 @@ class LayoutFrameSet final : public LayoutBox {
   GridAxis cols_;
 
   bool is_resizing_;
-  bool is_child_resizing_;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutFrameSet, IsFrameSet());