[LayoutNG] Implement container overflow inline padding

Container adds inline_end padding to inline children

Bug: 728378
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_layout_tests_layout_ng
Change-Id: I43008ae9ec0b201eff0197fe457bc3a7483e4566
Reviewed-on: https://chromium-review.googlesource.com/1068139
Commit-Queue: Aleks Totic <atotic@chromium.org>
Reviewed-by: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#560810}

third_party/WebKit/LayoutTests/FlagExpectations/enable-blink-features=LayoutNG

@@ -1258,7 +1258,6 @@ crbug.com/591099 media/video-poster-scale.html [ Failure ]
 crbug.com/591099 media/video-replaces-poster.html [ Failure ]
 crbug.com/591099 media/video-zoom.html [ Failure ]
 crbug.com/591099 netinfo/estimate-multiple-frames.html [ Failure Pass ]
-crbug.com/728378 overflow/overflow-inline-001.html [ Failure ]
 crbug.com/591099 paint/inline/focus-ring-under-absolute-with-relative-continuation.html [ Failure ]
 crbug.com/591099 paint/invalidation/background/backgroundSizeRepaint.html [ Failure ]
 crbug.com/591099 paint/invalidation/block-layout-inline-children-replaced.html [ Failure ]

third_party/blink/renderer/core/layout/ng/geometry/ng_physical_offset_rect.cc

@@ -4,6 +4,7 @@
 
 #include "third_party/blink/renderer/core/layout/ng/geometry/ng_physical_offset_rect.h"
 
+#include "third_party/blink/renderer/core/layout/ng/geometry/ng_box_strut.h"
 #include "third_party/blink/renderer/core/style/computed_style.h"
 #include "third_party/blink/renderer/platform/geometry/float_rect.h"
 #include "third_party/blink/renderer/platform/geometry/layout_rect.h"
@@ -36,6 +37,23 @@ void NGPhysicalOffsetRect::Unite(const NGPhysicalOffsetRect& other) {
   size = {right - left, bottom - top};
 }
 
+void NGPhysicalOffsetRect::Expand(const NGPhysicalBoxStrut& strut) {
+  if (strut.top) {
+    offset.top -= strut.top;
+    size.height += strut.top;
+  }
+  if (strut.bottom) {
+    size.height += strut.bottom;
+  }
+  if (strut.left) {
+    offset.left -= strut.left;
+    size.width += strut.left;
+  }
+  if (strut.right) {
+    size.width += strut.right;
+  }
+}
+
 NGPhysicalOffsetRect::NGPhysicalOffsetRect(const LayoutRect& source)
     : NGPhysicalOffsetRect({source.X(), source.Y()},
                            {source.Width(), source.Height()}) {}

third_party/blink/renderer/core/layout/ng/geometry/ng_physical_offset_rect.h

@@ -15,6 +15,7 @@ namespace blink {
 class ComputedStyle;
 class FloatRect;
 class LayoutRect;
+struct NGPhysicalBoxStrut;
 
 // NGPhysicalOffsetRect is the position and size of a rect (typically a
 // fragment) relative to its parent rect in the physical coordinate system.
@@ -37,6 +38,8 @@ struct CORE_EXPORT NGPhysicalOffsetRect {
 
   void Unite(const NGPhysicalOffsetRect&);
 
+  void Expand(const NGPhysicalBoxStrut&);
+
   // Conversions from/to existing code. New code prefers type safety for
   // logical/physical distinctions.
   explicit NGPhysicalOffsetRect(const LayoutRect&);

third_party/blink/renderer/core/layout/ng/layout_ng_mixin.cc

@@ -62,22 +62,33 @@ 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) {
+      // LayoutOverflow is only computed if overflow is not hidden
+      if (physical_fragment->Style().OverflowX() != EOverflow::kHidden ||
+          physical_fragment->Style().OverflowY() != EOverflow::kHidden) {
+        // inline-end LayoutOverflow padding spec is still undecided:
+        // https://github.com/w3c/csswg-drafts/issues/129
+        // For backwards compatibility, if container clips overflow,
+        // padding is added to the inline-end for inline children.
+        base::Optional<NGPhysicalBoxStrut> padding_strut;
+        if (Base::HasOverflowClip()) {
+          padding_strut =
+              NGBoxStrut(LayoutUnit(), Base::PaddingEnd(), LayoutUnit(),
+                         LayoutUnit())
+                  .ConvertToPhysical(Base::StyleRef().GetWritingMode(),
+                                     Base::StyleRef().Direction());
+        }
+        NGPhysicalOffsetRect children_overflow;
         for (const auto& child : physical_fragment->Children()) {
-          NGPhysicalOffsetRect child_overflow_rect =
+          NGPhysicalOffsetRect child_scrollable_overflow =
               child->ScrollableOverflow();
-          child_overflow_rect.offset += child->Offset();
-          if (!has_width)
-            child_overflow_rect.size.width = LayoutUnit();
-          if (!has_height)
-            child_overflow_rect.size.height = LayoutUnit();
-          Base::AddLayoutOverflow(child_overflow_rect.ToLayoutFlippedRect(
-              physical_fragment->Style(), physical_fragment->Size()));
+          child_scrollable_overflow.offset += child->Offset();
+          if (child->IsLineBox() && padding_strut) {
+            child_scrollable_overflow.Expand(*padding_strut);
+          }
+          children_overflow.Unite(child_scrollable_overflow);
         }
+        Base::AddLayoutOverflow(children_overflow.ToLayoutFlippedRect(
+            physical_fragment->Style(), physical_fragment->Size()));
       }
       Base::AddSelfVisualOverflow(
           physical_fragment->SelfVisualRect().ToLayoutFlippedRect(