[ng_layout] Fix wrong percent_resolution_size

third_party/WebKit/Source/core/layout/ng/ng_constraint_space.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_constraint_space.h"
 
 #include "core/layout/LayoutBlock.h"
 #include "core/layout/LayoutView.h"
 #include "core/layout/ng/ng_constraint_space_builder.h"
 #include "core/layout/ng/ng_layout_opportunity_iterator.h"
@@ skipping 52 matching lines @@
   if (box.hasOverrideLogicalContentHeight()) {
     available_logical_height = box.borderAndPaddingLogicalHeight() +
                                box.overrideLogicalContentHeight();
     fixed_block = true;
   }
 
   bool is_new_fc =
       box.isLayoutBlock() && toLayoutBlock(box).createsNewFormattingContext();
 
   NGLogicalSize size = {available_logical_width, available_logical_height};
+  NGLogicalSize percentage_size = {
+      box.containingBlockLogicalWidthForContent(),
+      box.containingBlockLogicalHeightForContent(IncludeMarginBorderPadding)};

[cbiesinger, 2017/01/09 18:17:10]

OK, a few questions:
- Here you explicitly choose containingBlockLogicalHeightForContent instead of
availableLogicalHeightForPercentageComputation for percentage resolution. Why?
The latter is supposed to be the correct one and if it isn't we should fix that
- Why is the available space supposed to be different from the percentage size
here?
- If this is in fact correct you should use ExcludeMarginBorderPadding right?

I assume this is for the !fixed_block case.

[atotic, 2017/01/09 23:22:13]

You are right. The real problem was that available_sizes were overridden by 
hasOverrideLogicalContentWidth afterwards.

New fix just saves percentage_size before we override available_size with
OverrideLogicalContentSize.

   auto writing_mode = FromPlatformWritingMode(box.styleRef().getWritingMode());
   return NGConstraintSpaceBuilder(writing_mode)
       .SetAvailableSize(size)
-      .SetPercentageResolutionSize(size)
+      .SetPercentageResolutionSize(percentage_size)
       .SetIsInlineDirectionTriggersScrollbar(
           box.styleRef().overflowInlineDirection() == EOverflow::Auto)
       .SetIsBlockDirectionTriggersScrollbar(
           box.styleRef().overflowBlockDirection() == EOverflow::Auto)
       .SetIsFixedSizeInline(fixed_inline)
       .SetIsFixedSizeBlock(fixed_block)
       .SetIsShrinkToFit(
           box.sizesLogicalWidthToFitContent(box.styleRef().logicalWidth()))
       .SetIsNewFormattingContext(is_new_fc)
       .SetTextDirection(box.styleRef().direction())
@@ skipping 21 matching lines @@
 
 String NGConstraintSpace::ToString() const {
   return String::format("%s,%s %sx%s",
                         offset_.inline_offset.toString().ascii().data(),
                         offset_.block_offset.toString().ascii().data(),
                         AvailableSize().inline_size.toString().ascii().data(),
                         AvailableSize().block_size.toString().ascii().data());
 }
 
 }  // namespace blink