[LayoutNG] Add LayoutOverflow for NG Children

I had to update bad expectations for several files.
New expectations match Legacy.

Bug: 728378
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_layout_tests_layout_ng
Change-Id: I64c10c269dd38f55a707cb7a0135f9f3a1207b97
Reviewed-on: https://chromium-review.googlesource.com/971465Reviewed-by: Koji Ishii <kojii@chromium.org>
Commit-Queue: Aleks Totic <atotic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544643}

third_party/WebKit/LayoutTests/TestExpectations

@@ -274,9 +274,6 @@ crbug.com/704961 [ Mac ] virtual/layout_ng/external/wpt/css/CSS2/normal-flow/wid
 # Block: percent height in continuations.
 crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/normal-flow/block-in-inline-percents-001.xht [ Failure ]
 
-# Block: percent max-height.
-crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/normal-flow/max-height-percentage-002.xht [ Failure ]
-
 # Inline: border in continuations. Fail in Blink.
 crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/normal-flow/block-in-inline-empty-001.xht [ Failure ]
 crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/normal-flow/block-in-inline-empty-004.xht [ Failure ]

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/css1/color_and_background/background_attachment-expected.txt

-layer at (0,0) size 800x600 scrollHeight 1279
+layer at (0,0) size 800x600 scrollWidth 880 scrollHeight 1279
   LayoutView at (0,0) size 800x600
 layer at (0,0) size 800x1279 backgroundClip at (0,0) size 800x600 clip at (0,0) size 800x600
   LayoutNGBlockFlow {HTML} at (0,0) size 800x1278.53

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/css1/color_and_background/background_repeat-expected.txt

-layer at (0,0) size 800x600 scrollHeight 1993
+layer at (0,0) size 800x600 scrollWidth 888 scrollHeight 1993
   LayoutView at (0,0) size 800x600
 layer at (0,0) size 800x1993 backgroundClip at (0,0) size 800x600 clip at (0,0) size 800x600
   LayoutNGBlockFlow {HTML} at (0,0) size 800x1993

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/css2.1/t1202-counters-08-b-expected.txt

-layer at (0,0) size 800x600
+layer at (0,0) size 800x600 scrollWidth 954
   LayoutView at (0,0) size 800x600
 layer at (0,0) size 800x100
   LayoutNGBlockFlow {HTML} at (0,0) size 800x100

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/fast/css/line-thickness-underline-strikethrough-overline-expected.txt

-layer at (0,0) size 800x600
+layer at (0,0) size 800x600 scrollWidth 1031
   LayoutView at (0,0) size 800x600
 layer at (0,0) size 800x251
   LayoutNGBlockFlow {HTML} at (0,0) size 800x251

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

@@ -56,6 +56,21 @@ void LayoutNGMixin<Base>::AddOverflowFromChildren() {
   // Add overflow from the last layout cycle.
   if (Base::ChildrenInline()) {
     if (const NGPhysicalBoxFragment* physical_fragment = CurrentFragment()) {
+      bool has_width =
+          physical_fragment->Style().OverflowX() != EOverflow::kHidden;
+      bool has_height =
+          physical_fragment->Style().OverflowY() != EOverflow::kHidden;
+      if (has_width || has_height) {
+        for (const auto& child : physical_fragment->Children()) {
+          NGPhysicalOffsetRect child_rect(child->Offset(), child->Size());
+          if (!has_width)
+            child_rect.size.width = LayoutUnit();
+          if (!has_height)
+            child_rect.size.height = LayoutUnit();
+          Base::AddLayoutOverflow(child_rect.ToLayoutRect());
+        }
+      }
+
       // TODO(kojii): If |RecalcOverflowAfterStyleChange()|, we need to
       // re-compute glyph bounding box. How to detect it and how to re-compute
       // is TBD.