[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..56256ff489198c2eea435266aac86240c8a7157a 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
@@ -52,6 +52,8 @@ NGConstraintSpace* NGConstraintSpace::CreateFromLayoutObject(
     available_logical_height =
         box.containingBlock()->availableLogicalHeightForPercentageComputation();
   }
+  NGLogicalSize percentage_size = {available_logical_width,
+                                   available_logical_height};
   // When we have an override size, the available_logical_{width,height} will be
   // used as the final size of the box, so it has to include border and
   // padding.
@@ -69,11 +71,12 @@ NGConstraintSpace* NGConstraintSpace::CreateFromLayoutObject(
   bool is_new_fc =
       box.isLayoutBlock() && toLayoutBlock(box).createsNewFormattingContext();
 
-  NGLogicalSize size = {available_logical_width, available_logical_height};
+  NGLogicalSize logical_size = {available_logical_width,

[cbiesinger, 2017/01/10 22:00:50]

available_size is better. But I also meant if you could move this line above,
right under percentage_size.


Ah... I think I figured it out wrt the old codepath... two reasons:
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/layout/La...
gets called before we check for overrideLogicalContentWidth. But also:

https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/layout/La...
We ignore the override width unless we're a flex item. Should probably change
that.

[atotic, 2017/01/10 23:24:15]

logical_size can't go right under percentage_size, because 
available_logical_height gets recomputed in between those two statements.
I am shy when it comes to editing old code, unless I am explicitly fixing
an existing bug. My knowledge of existing code paths is limitied,
and I fear unexpected dependencies.

Do you want to do old code work, or should I just follow your advice?

[cbiesinger, 2017/01/10 23:26:36]

I'll send a followup patch once this lands, I think that'll help in explaining
what I mean and then we can discuss whether it's a good idea :-)
I can do that tomorrow.

+                                available_logical_height};
   auto writing_mode = FromPlatformWritingMode(box.styleRef().getWritingMode());
   return NGConstraintSpaceBuilder(writing_mode)
-      .SetAvailableSize(size)
-      .SetPercentageResolutionSize(size)
+      .SetAvailableSize(logical_size)
+      .SetPercentageResolutionSize(percentage_size)
       .SetIsInlineDirectionTriggersScrollbar(
           box.styleRef().overflowInlineDirection() == EOverflow::Auto)
       .SetIsBlockDirectionTriggersScrollbar(