[ng_layout] Fix wrong percent_resolution_size

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

Index: third_party/WebKit/Source/core/layout/ng/ng_constraint_space.cc
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_constraint_space.cc b/third_party/WebKit/Source/core/layout/ng/ng_constraint_space.cc
index 5af006f4649233d7cc55059be4c0fa0b5c8e8fce..43842676ee03d70f65598f4aebe27c97f5b77ff2 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_constraint_space.cc
+++ b/third_party/WebKit/Source/core/layout/ng/ng_constraint_space.cc
@@ -70,10 +70,13 @@ NGConstraintSpace* NGConstraintSpace::CreateFromLayoutObject(
       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(