Take into account fragment's margins while searching opportunities.

third_party/WebKit/Source/core/layout/ng/ng_block_layout_algorithm.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/layout/ng/ng_block_layout_algorithm.h"
 
 #include "core/layout/ng/ng_constraint_space.h"
 #include "core/layout/ng/ng_fragment_builder.h"
 #include "core/layout/ng/ng_fragment.h"
 #include "core/layout/ng/ng_layout_opportunity_iterator.h"
@@ skipping 37 matching lines @@
 }
 
 // Finds a layout opportunity for the fragment.
 // It iterates over all layout opportunities in the constraint space and returns
 // the first layout opportunity that is wider than the fragment or returns the
 // last one which is always the widest.
 //
 // @param space Constraint space that is used to find layout opportunity for
 //              the fragment.
 // @param fragment Fragment that needs to be placed.
+// @param margins Margins of the fragment.
 // @return Layout opportunity for the fragment.
 const NGLayoutOpportunity FindLayoutOpportunityForFragment(
     const Member<NGConstraintSpace>& space,
-    const NGFragment& fragment) {
+    const NGFragment& fragment,
+    const NGBoxStrut& margins) {
   NGLayoutOpportunityIterator* opportunity_iter = space->LayoutOpportunities();
   NGLayoutOpportunity opportunity;
   NGLayoutOpportunity opportunity_candidate = opportunity_iter->Next();
 
   while (!opportunity_candidate.IsEmpty()) {
     opportunity = opportunity_candidate;
     // Checking opportunity's block size is not necessary as a float cannot be
     // positioned on top of another float inside of the same constraint space.
-    if (opportunity.size.inline_size > fragment.InlineSize())
+    auto fragment_inline_size = fragment.InlineSize() + margins.InlineSum();
+    if (opportunity.size.inline_size > fragment_inline_size)
       break;
 
     opportunity_candidate = opportunity_iter->Next();
   }
 
   return opportunity;
 }
 
 // Calculates the logical offset for opportunity.
 NGLogicalOffset CalculateLogicalOffsetForOpportunity(
@@ skipping 239 matching lines @@
                             border_and_padding_.InlineSum());
   return NGLogicalOffset(inline_offset, block_offset);
 }
 
 NGLogicalOffset NGBlockLayoutAlgorithm::PositionFloatFragment(
     const NGFragment& fragment,
     const NGBoxStrut& margins) {
   // TODO(glebl@chromium.org): Support the top edge alignment rule.
   // Find a layout opportunity that will fit our float.
   const NGLayoutOpportunity opportunity = FindLayoutOpportunityForFragment(
-      constraint_space_for_children_, fragment);
+      constraint_space_for_children_, fragment, margins);
   DCHECK(!opportunity.IsEmpty()) << "Opportunity is empty but it shouldn't be";
 
   // Calculate the float offset if needed.
   LayoutUnit float_offset;
   if (current_child_->Style()->floating() == EFloat::Right) {
     float_offset = opportunity.size.inline_size - fragment.InlineSize();
   }
 
   // Add the float as an exclusion.
-  NGExclusion* exclusion =
+  const NGExclusion* exclusion =
       CreateExclusion(fragment, opportunity, float_offset, margins);
   constraint_space_for_children_->AddExclusion(exclusion);
 
   return CalculateLogicalOffsetForOpportunity(opportunity, border_and_padding_,
                                               float_offset, margins);
 }
 
 void NGBlockLayoutAlgorithm::UpdateMarginStrut(const NGMarginStrut& from) {
   if (!is_fragment_margin_strut_block_start_updated_) {
     builder_->SetMarginStrutBlockStart(from);
     is_fragment_margin_strut_block_start_updated_ = true;
   }
   builder_->SetMarginStrutBlockEnd(from);
 }
 
 }  // namespace blink