Resolve inline margins in over-constrained situations correctly.

third_party/WebKit/Source/core/layout/LayoutBox.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc.
  *               All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 2690 matching lines @@
       kInlineDirection, cb, container_logical_width, computed_values.extent_,
       computed_values.margins_.start_, computed_values.margins_.end_,
       Style()->MarginStart(), Style()->MarginEnd());
 
   if (!has_perpendicular_containing_block && container_logical_width &&
       container_logical_width !=
           (computed_values.extent_ + computed_values.margins_.start_ +
            computed_values.margins_.end_) &&
       !IsFloating() && !IsInline() && !cb->IsFlexibleBoxIncludingDeprecated() &&
       !cb->IsLayoutGrid()) {
-    LayoutUnit new_margin = container_logical_width - computed_values.extent_ -
-                            cb->MarginStartForChild(*this);
+    LayoutUnit new_margin_total =
+        container_logical_width - computed_values.extent_;
     bool has_inverted_direction = cb->Style()->IsLeftToRightDirection() !=
                                   Style()->IsLeftToRightDirection();
-    if (has_inverted_direction)
-      computed_values.margins_.start_ = new_margin;
-    else
-      computed_values.margins_.end_ = new_margin;
+    if (has_inverted_direction) {
+      computed_values.margins_.start_ =
+          new_margin_total - computed_values.margins_.end_;
+    } else {
+      computed_values.margins_.end_ =
+          new_margin_total - computed_values.margins_.start_;
+    }
   }
 
   if (style_to_use.TextAutosizingMultiplier() != 1 &&
       style_to_use.MarginStart().GetType() == kFixed) {
     Node* parent_node = GeneratingNode();
     if (parent_node && (isHTMLOListElement(*parent_node) ||
                         isHTMLUListElement(*parent_node))) {
       // Make sure the markers in a list are properly positioned (i.e. not
       // chopped off) when autosized.
       const float adjusted_margin =
@@ skipping 3171 matching lines @@
 void LayoutBox::MutableForPainting::
     SavePreviousContentBoxSizeAndLayoutOverflowRect() {
   auto& rare_data = GetLayoutBox().EnsureRareData();
   rare_data.has_previous_content_box_size_and_layout_overflow_rect_ = true;
   rare_data.previous_content_box_size_ = GetLayoutBox().ContentBoxRect().Size();
   rare_data.previous_layout_overflow_rect_ =
       GetLayoutBox().LayoutOverflowRect();
 }
 
 }  // namespace blink